The TWRP that comes with FP OS does not work in ADB mode (afaik), however, if the latest TWRP community port is installed, it is possible to use ADB while being in TWRP.
The TWRP that comes with FP OS does not work in ADB mode (afaik), however, if the latest TWRP community port is installed, it is possible to use ADB while being in TWRP.