How to connect SourceTree to GitHub Enterprise Server that uses SAML auth.

[Kurt Larson]

I'd like connect SourceTree on Windows10 version 3.4.10 to GitHub Enterprise Server 3.4.9 hosted on EC2 in an AWS account.  I can't seem to get HTTPS authentication using a GitHub Personal Access Token (PAT) to work.   

The GItHub Enterprise Server instance is using Okta SAML to authenticate GitHub users. 

After configuring the GitHub account in SourceTree using HTTPS and my PAT as the password SourceTree seems to authenticate OK, but when I try to use the show the repos from an Organization in GitHub (I have access to many GitHub Organizations) I can't get a list of repos.