The exact error message we are seeing is:
ERROR 1 photonVision coprocessor at path /photonvision/RoxCam2021-4361 not found on NetworkTables!
FIrst, I would look at what @Starlight220 said and follow those steps.
Next, you have another issue, a version mismatch between your PhotonLib vendor dependency judging from this code
On your coprocessor, you are running some dev version of PhotonVision according to the logs.
To fix this, change the 2021.1.2 in your vendordep to 2021.1.7 you have now and download the 2021.1.7 release. . You might notice that there is a 2021.1.8 release out, but stick with 2021.1.7 for now because there are some minor versioning issues with it at the moment.
If you have any issues after this, please let us know,