Use SSH ULR to create Mirroring repositories with Github

I would like to add github repositories to mirroring.
However, always return Permission denied.

I have tested on terminal:

git clone ssh://git@github.com/username/project_name.git

And it succeed.

While enter ssh://git@github.com/username/project_name.git on gitlab, it dosen’t work.

How should I do? Thanks.

Oh, I found the solution.

Git repository URL: https://github.com/username/project.git
Username: Personal access tokens
Password: Blank

Then finally, it will become git clone https://TOKEN@github.com/username/project.git
And it succeed.