Add an API endpoint to GET SSH keys
You have a way to add, update, and delete SSH keys via the API, but there is no way to list SSH keys. Therefore, if you want to update or delete an SSH key (especially one that you added via the control panel) there is no way to do it via the API because you don't know the SSH key ID.
Heath Dutton commented
Not sure if it helps you, but you can list application-level ssh credentials.