At the moment, the best way to connect Pharo to GitHub is through personal access tokens. Follow the following steps, one step at a time.
Create a person access token on GitHub.
Go to https://github.com/settings/tokens or follow the instructions on the GitHub docs.
Generate a new token. I would set it to last for 90 days.
The token should have the full repo scope, as seen on the right.
Copy the token and place it in a temporary text file.
Alternately, you can perform steps 2-3 first, and generate the token after step 3.
In Iceberg, click "Add a repository", and then "Clone remote repository".
It does not work using "Clone from github.com".
On GitHub, go to a repository, click code, and copy the HTTPS link.
You can use any GitHub repo to set this up, I used
https://github.com/TU-CSCI3362-SP22/dice-roller.git
If necessary, you can forget an existing repository. You may have to navigate to the directory in order to delete the folder.
Enter your username and the token as the password.
Click "Do you want this credentials to be stored for future use?"
You will not be able to copy the token from GitHub again.
Everything should work now. This may also fix problems on MacOS.