I am thinking of using it, but how would I do it with RobotC?
Keep your source files for a particular project in a separate folder.
Put the folder under revision control using git, see apps below.
Edit in RobotC as usual, when you have made changes to the code, save the file in RobotC then commit and push to your remote repo using your git client application.
I use a dedicated git application, I do not use any of the git support built into editors such as VS Code (the changes display but I never commit or push using those tools). My favorite git client is Tower, but it is not free.