My students can't push to their github accounts

I teach a class of beginners using Android Studio and github for the first time. This semester they are running into a lot of trouble, one in particular got this message:

3:32 PM Can’t finish GitHub sharing process
Successfully created project ‘MyApplicationv2021x’ on GitHub, but initial push failed:
Warning: Permanently added the RSA host key for IP address ‘140.82.113.4’ to the list of known hosts.
git@github.com: Permission denied (publickey).
Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.

her account is here: al37025p/Github · GitHub

I just had a zoom meeting with her, and had her set up a brand new account on github, and then try again to share the project via Android Studio, she keeps getting this “permission denied” message. Other students got similar messages, but they were able to get it working after creating a new github account. She is particularly stuck.
Any suggestions?
Cathy Dwyer at Pace University cdwyer@pace.edu

You can either use SSH or HTTPS to push commits to GitHub.

HTTPS is in general easier to use and therefore the go to solution for your students. If you push it via HTTPS, a new window opens where you have to insert your GitHub credentials once. This will then be stored in a local credentials store on the computer.

For SSH, you have to generate a new pair and add the public key to the GitHub account.
This is described here: Generating a new SSH key and adding it to the ssh-agent - GitHub Docs

You can also use the GitHub CLI tool: