Creating a git repository with gitlab, not work?

I'm at "Manage files using Source Control". When I paste the https link into repository path, I get this error: "cannot open git-upload-pack." When I paste the ssh link into repository path, I get "Algorithm Negotiation Fail"

However, on gitlab it is saying: "You won't be able to pull or push project code via SSH until you add an SSH key to your profile." Is this relevant? I never once before had to create an SSH key when dealing with cloning a git repository.

--Edit--

Just now I manually cloned the git repository into my directory. Now, I'm trying to integrate with Matlab and it's giving me a different error: "Could not checkout repository at location:" What could be the problem?