I have SourceTree with local working copy. And all operations work good, I can simple fetch, push, pull and etc via SourceTree. I just needed to make force push which does not exist in SourceTree.
I opened terminal made git push -f
remote: Repository not found.fatal: repository 'https://github.com/MyRepo/project.git/' not found
remote: Repository not found.
fatal: repository 'https://github.com/MyRepo/project.git/' not found
I am not sure what can be an issue.
Removing all github.com credential details from the system would be the simplest way of fixing this issue.
Delete the github.com password from the Keychain Access.
Delete the credentials from Credential Manager.