Git command doesn't work

[Codinablack]

I have tried using powershell, git bash, and cmd with your command, all of which under administrator/elevated privileges, and all of which were properly cd'd to the correct directory (which clearly has no bearing on this type of error anyways), and each and every time the bash/terminal returns to me this error.

"fatal: not a git repository (or any of the parent directories): .git"

The command I was using was the one listed on projects main page

git submodule add https://github.com/lubgr/lua-cmake external/lua

[Mister-Ky]

try using git to create and initialize a repository
in your case, you don't have a repository and git doesn't know who to add the submodule to