After cloning your repo on your local PC, add the submodules with:
git submodule add https://github.com/yourusername/myrepo.git
To update with the content all the submodules use inside root:
git submodule init
git submodule update
When changes were made to a submodule do this setup first:
git checkout main
Then inside any Repo use it as usual
Then for new updates use:
git submodule update --remote
For manual push use:
git push origin main