Confirm thusly:
And really one ought to also take the sha256 hash and check that one matches what GitHub has published at: GitHub's SSH key fingerprints - GitHub Docs. You need to cross-reference with a known, trusted fingerprint to actually confirm anything. Bash one-liner left at an exercise to the reader, but consider that technically it is important to take both hashes of the same key, so run ssh-keyscan once and hash the result with each hash algorithm.