How should I organize the backend and frontend of my code?

I have a project and I've written a lot of code for the backend (Flask / Python) and a lot of code for the front end (Vue). Up until now they've been separate folders / Github repos.

I was wondering what was typical for combining them together with respect to (1) Github repositories and (2) file structure. The front end depends on some functions in the backend, so they'd need to be linked in some way, but since there is so much code for both aspects of the project, I thought it might be overwhelming to just combine them under one Github repository / file structure.

Could anyone offer some suggestions or resources?