Can the built in flash be popped up manually in the creative zone ie (M, Av, TV & P) modes.
If it is not popping up you can help it. Set the camera so that it will try to pop the flash up and quickly use your finger nail in the crack between it and the camera to help it. It is common for dirt to get on the linkage which becomes inoperative. A drop of alcohol will clean it and a tiny, tiny drop or WD40 will lube it.
If it pops up but doesn't flash the bulb is probably blown out.
If it will not pop up, it may be caused by a stuck switch plunger on the side of the hot shoe. Its purpose is to detect if an external flash is in the hot shoe to keep the internal flash from popping up and hitting the external flash. If this is the case, you can clean the plunger to free it up.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.