Hi Lucas,
are you running the official TBC v2024.0x or a beta build? We did integrate the support of DJI L1 and L2 in the latest beta builds (don't put me on the line but it should be part of the October builds and later), as there are a couple of steps to be done to the trajectory data to get it running in TBC.
The L1 and L2 sensors and corresponding M300 or M350 drones do not create the standard obs file. You get by default RTK files. TBC converts them in the upcoming version to a Rinex OBS file, because the RTK file is based on RTCM 3. With the converted Rinex OBS file a PPK trajectory can be processed, if you put the OBS file in the folder with the images.
The new beta build will automatically convert the RTCM 3 RTK file into a Rinex OBS file for DJI L1 and L2 image data and should work with the default outputs from these DJI drones.
When running the beta build you can check if TBC created a Rinex OBS fie in the image folder.
Hope this helps.