SSH keys generated by puttygen will not import

My ed25519 keys are generated by puttygen. I’ve tried to export the key using puttygen but bitwarden reports that the keys are invalid when trying to import. Do we know what the output difference is between ssh-keygen and puttygen?

Is there a way to convert a puttygen ssh key to a format compatible with bitwarden. It works in keepass keeagent.