For the T-GT on PlayStation you need to set the switch of the base in OTHER position (and not in GT position) before plugging the usb of the wheel.
The GT position is only for GRAN TURISMO games.
When done, in the options of F1 23 - PS5 you just have to select THRUSTMASTER ADVANCED RACER.
For the T248 Xbox version you need to:
Step 1) Install the new driver [Package 2023_TTRS_3] available here the DRIVERS tab: https://support.thrustmaster.com/en/product/t248x-en/
Step 2) When done launch THRUSTMASTER FIRMWARE UPDATE software and install manually the new firmware V2.03.
Full process is explain here: https://ts.thrustmaster.com/download/pub/webupdate/t500rs/T248-X_Firmware_Update_Procedure_v203.pdf
When done open the T248 Control Panel, and check that the firmware version is V2.03 as show here: https://ts.thrustmaster.com/download/pictures/PCMAC/T248/T248-X_CPL_FW_v2_03.png
