Git repo organization for cloud deployment

I'm having trouble figuring out the best git repository organization for a web app that is going to be hosted on Azure.

For example, I want all of my code to be monorepo, but I need to have separate sections of code that I can push to the individual Azure services eg: Web App and API App as if I push the entire project to an API app, it will not understand how to execute just the API.

Is best practice for cloud deployment to have submodules or to have individual projects/repos for each section?