Thanks for your help, abcd567, foxhunter.
OK, was missing the repo, followed step 3, looking better already:
> $ grep ^[^#] /etc/apt/sources.list /etc/apt/sources.list.d/*
> /etc/apt/sources.list:deb http://deb.debian.org/debian bookworm main contrib non-free non-free-firmware
> /etc/apt/sources.list:deb http://deb.debian.org/debian-security/ bookworm-security main contrib non-free non-free-firmware
> /etc/apt/sources.list:deb http://deb.debian.org/debian bookworm-updates main contrib non-free non-free-firmware
> /etc/apt/sources.list.d/fr24feed.list:deb [signed-by=/etc/apt/keyrings/flightradar24.gpg] https://repo-feed.flightradar24.com flightradar24 raspberrypi-stable
> /etc/apt/sources.list.d/raspi.list:deb http://archive.raspberrypi.com/debian/ bookworm main
>
>
> $ wget https://www.flightaware.com/adsb/piaware/files/packages/pool/piaware/f/flightaware-apt-repository/flightaware-apt-repository_1.2_all.deb
> --2025-05-24 23:15:53-- https://www.flightaware.com/adsb/piaware/files/packages/pool/piaware/f/flightaware-apt-repository/flightaware-apt-repository_1.2_all.deb
> Resolving www.flightaware.com (www.flightaware.com)... 104.18.39.201, 172.64.148.55, 2606:4700:4400::6812:27c9, ...
> Connecting to www.flightaware.com (www.flightaware.com)|104.18.39.201|:443... connected.
> HTTP request sent, awaiting response... 200 OK
> Length: 4996 (4.9K) [application/x-debian-package]
> Saving to: ‘flightaware-apt-repository_1.2_all.deb’
>
> flightaware-apt-reposito 100%[==================================>] 4.88K --.-KB/s in 0s
>
> 2025-05-24 23:15:53 (14.5 MB/s) - ‘flightaware-apt-repository_1.2_all.deb’ saved [4996/4996]
>
> voytek@rpi2:~ $ sudo dpkg -i flightaware-apt-repository_1.2_all.deb
> Selecting previously unselected package flightaware-apt-repository.
> (Reading database ... 182347 files and directories currently installed.)
> Preparing to unpack flightaware-apt-repository_1.2_all.deb ...
> Unpacking flightaware-apt-repository (1.2) ...
> Setting up flightaware-apt-repository (1.2) ...
> flightaware-apt-repository: regenerated APT configuration /etc/apt/sources.list.d/flightaware-apt-repository.list
> flightaware-apt-repository: please run 'sudo apt update' to use the new configuration
>
> $ grep ^[^#] /etc/apt/sources.list /etc/apt/sources.list.d/* /etc/apt/sources.list:deb http://deb.debian.org/debian bookworm main contrib non-free non-free-firmware
> /etc/apt/sources.list:deb http://deb.debian.org/debian-security/ bookworm-security main contrib non-free non-free-firmware
> /etc/apt/sources.list:deb http://deb.debian.org/debian bookworm-updates main contrib non-free non-free-firmware
> /etc/apt/sources.list.d/flightaware-apt-repository.list:deb [ signed-by=/usr/share/keyrings/flightaware-archive-keyring.gpg ] http://flightaware.com/adsb/piaware/files/packages bookworm piaware
> /etc/apt/sources.list.d/fr24feed.list:deb [signed-by=/etc/apt/keyrings/flightradar24.gpg] https://repo-feed.flightradar24.com flightradar24 raspberrypi-stable
> /etc/apt/sources.list.d/raspi.list:deb http://archive.raspberrypi.com/debian/ bookworm main
> $
now it gets offered as a in place upgrade, I guess I should do just that?
$ grep ^[^#] /etc/apt/sources.list /etc/apt/sources.list.d/*
/etc/apt/sources.list:deb http://deb.debian.org/debian bookworm main contrib non-free non-free-firmware
/etc/apt/sources.list:deb http://deb.debian.org/debian-security/ bookworm-security main contrib non-free non-free-firmware
/etc/apt/sources.list:deb http://deb.debian.org/debian bookworm-updates main contrib non-free non-free-firmware
/etc/apt/sources.list.d/fr24feed.list:deb [signed-by=/etc/apt/keyrings/flightradar24.gpg] https://repo-feed.flightradar24.com flightradar24 raspberrypi-stable
/etc/apt/sources.list.d/raspi.list:deb http://archive.raspberrypi.com/debian/ bookworm main
$ wget https://www.flightaware.com/adsb/piaware/files/packages/pool/piaware/f/flightaware-apt-repository/flightaware-apt-repository_1.2_all.deb
--2025-05-24 23:15:53-- https://www.flightaware.com/adsb/piaware/files/packages/pool/piaware/f/flightaware-apt-repository/flightaware-apt-repository_1.2_all.deb
Resolving www.flightaware.com (www.flightaware.com)... 104.18.39.201, 172.64.148.55, 2606:4700:4400::6812:27c9, ...
Connecting to www.flightaware.com (www.flightaware.com)|104.18.39.201|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 4996 (4.9K) [application/x-debian-package]
Saving to: ‘flightaware-apt-repository_1.2_all.deb’
flightaware-apt-reposito 100%[==================================>] 4.88K --.-KB/s in 0s
2025-05-24 23:15:53 (14.5 MB/s) - ‘flightaware-apt-repository_1.2_all.deb’ saved [4996/4996]
voytek@rpi2:~ $ sudo dpkg -i flightaware-apt-repository_1.2_all.deb
Selecting previously unselected package flightaware-apt-repository.
(Reading database ... 182347 files and directories currently installed.)
Preparing to unpack flightaware-apt-repository_1.2_all.deb ...
Unpacking flightaware-apt-repository (1.2) ...
Setting up flightaware-apt-repository (1.2) ...
flightaware-apt-repository: regenerated APT configuration /etc/apt/sources.list.d/flightaware-apt-repository.list
flightaware-apt-repository: please run 'sudo apt update' to use the new configuration
$ grep ^[^#] /etc/apt/sources.list /etc/apt/sources.list.d/* /etc/apt/sources.list:deb http://deb.debian.org/debian bookworm main contrib non-free non-free-firmware
/etc/apt/sources.list:deb http://deb.debian.org/debian-security/ bookworm-security main contrib non-free non-free-firmware
/etc/apt/sources.list:deb http://deb.debian.org/debian bookworm-updates main contrib non-free non-free-firmware
/etc/apt/sources.list.d/flightaware-apt-repository.list:deb [ signed-by=/usr/share/keyrings/flightaware-archive-keyring.gpg ] http://flightaware.com/adsb/piaware/files/packages bookworm piaware
/etc/apt/sources.list.d/fr24feed.list:deb [signed-by=/etc/apt/keyrings/flightradar24.gpg] https://repo-feed.flightradar24.com flightradar24 raspberrypi-stable
/etc/apt/sources.list.d/raspi.list:deb http://archive.raspberrypi.com/debian/ bookworm main
$
$ sudo apt update Hit:1 http://deb.debian.org/debian bookworm InRelease
Get:2 http://deb.debian.org/debian-security bookworm-security InRelease [48.0 kB]
Hit:4 http://deb.debian.org/debian bookworm-updates InRelease
Hit:5 https://repo-feed.flightradar24.com flightradar24 InRelease
Get:3 https://www.flightaware.com/adsb/piaware/files/packages bookworm InRelease [2,613 B]
Hit:6 http://archive.raspberrypi.com/debian bookworm InRelease
Get:7 https://www.flightaware.com/adsb/piaware/files/packages bookworm/piaware arm64 Packages [4,681 B]
Get:8 https://www.flightaware.com/adsb/piaware/files/packages bookworm/piaware armhf Packages [5,659 B]
Fetched 60.9 kB in 1s (40.6 kB/s)
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
3 packages can be upgraded. Run 'apt list --upgradable' to see them.
$ sudo apt upgrade
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
The following NEW packages will be installed:
libestr0 libfastjson4 liblognorm5 rsyslog
The following packages will be upgraded:
dump1090-fa piaware piaware-web
3 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
Need to get 9,693 kB of archives.
After this operation, 6,327 kB of additional disk space will be used.
Do you want to continue? [Y/n] n
Abort.
Hit:1 http://deb.debian.org/debian bookworm InRelease
> Get:2 http://deb.debian.org/debian-security bookworm-security InRelease [48.0 kB]
> Hit:4 http://deb.debian.org/debian bookworm-updates InRelease
> Hit:5 https://repo-feed.flightradar24.com flightradar24 InRelease
> Get:3 https://www.flightaware.com/adsb/piaware/files/packages bookworm InRelease [2,613 B]
> Hit:6 http://archive.raspberrypi.com/debian bookworm InRelease
> Get:7 https://www.flightaware.com/adsb/piaware/files/packages bookworm/piaware arm64 Packages [4,681 B]
> Get:8 https://www.flightaware.com/adsb/piaware/files/packages bookworm/piaware armhf Packages [5,659 B]
> Fetched 60.9 kB in 1s (40.6 kB/s)
> Reading package lists... Done
> Building dependency tree... Done
> Reading state information... Done
> 3 packages can be upgraded. Run 'apt list --upgradable' to see them.
>
>
> $ sudo apt upgrade
> Reading package lists... Done
> Building dependency tree... Done
> Reading state information... Done
> Calculating upgrade... Done
> The following NEW packages will be installed:
> libestr0 libfastjson4 liblognorm5 rsyslog
> The following packages will be upgraded:
> dump1090-fa piaware piaware-web
> 3 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
> Need to get 9,693 kB of archives.
> After this operation, 6,327 kB of additional disk space will be used.
> Do you want to continue? [Y/n] n
> Abort.