How to connect GIT submodule correctly?

Question

git

There is a class wrapper in the form of a module (for example, some kind for CMS), how to correctly include the files of this third-party class as a submodule in GIT?
Our repository

..
vendor/Mod

Class repository:

api/php/Mod/mod.php
api/python/Mod/mod.py
..
cpp/
*.js
..
README.txt

That is, a third-party repository has an API for several languages ​​+ stores other files we don’t need (for example, for the full operation of the module, you only need a file file along the path api/php/Mod/mod.php) How to connect this repository correctly (i.e. only the required class without "extra" files, or do you still need to connect the entire repository in the form in which it is?

Answer 1

you need to connect the entire repository in the form in which it is

You answered yourself