You’re using an RSA key with SHA-1, which is no longer allowed

When I tried to upload my app source in a long time, I met this error.
This means that we can’t use RSA SSH Key for Github any more.

Last year, I generated SSH key with RSA instead of ed25519 for my personal app source.
Because XCode didn’t support ed25519, I had to use RSA instead.

ed25519

ssh-keygen -t ed25519 -C "your_email@example.com"

See how to create and add ed25519 key

XCode 13.3

Now XCode supports ed25519 since 13.3, so we can use ed25519 in XCode.
See this release note.

New Features

• Xcode now supports using ED25519 public key signatures to perform git operations.

References

Improving Git protocol security on GitHub | The GitHub Blog

Apple Developer Documentation

Generating a new SSH key and adding it to the ssh-agent - GitHub Docs