GitLab + Visual Studio 2017

Hi all – I am attempting to use Visual Studio with GitLab but I keep getting this error
"Host key verfication failed.
Fatal: Could not read from remote repository.

Please make sure you have the correct access rights and the repository exists"

I’m not sure what I need to do to resolve this. I have a key that I use with SourceTree which works without problem, but I don’t see anywhere in VS to put in a key. Any ideas?