Thank you for your support.
I’ve done a fresh install in another RPi using the latest Piaware image, then a fresh install of Raspberry OS lite and still couldn’t add the "terrain limit rings.
Then I’ve done a fresh install of Piaware_3.7.2 and after having the file upintheair.json in /usr/share/dump1090-fa/html/upintheair.json I got the “terrain limit rings”.
