Cloning booted RPi’s microSD card if RPi is physically accessable.
Plug into RPi, a USB Card Reader/Writer, with backup microSD Card inserted into the card reader.
Case (1):
If Image is Raspberry Pi OS with desktop (GUI), it has a tool in accessories named SD Card Copier which very conveniently copies the booted microSD card
Case (2):
If image is Raspberry Pi OS Lite or Piaware SD Card image with no GUI, use the method below:
wget https://raw.githubusercontent.com/billw2/rpi-clone/master/rpi-clone
sudo bash rpi-clone sda -v
Please see this post:
https://www.raspberrypi.org/forums/viewtopic.php?t=180383#p1877328
For complete Guide:
https://github.com/billw2/rpi-clone