Connect button for SSH key is prompting for password

I have a valid SSH key in my vault, which is authorised with my server. If I export this key and use it directly with ssh -i [removed by moderator] then it works.

Following these instructions (https://www.1password.dev/ssh/bookmarks#in-an-ssh-key-item), I added a new field to the key with the hostname in the form ssh:// [removed by moderator] . This causes the Connect button to appear when I mouse over the key. However if I click the Connect button, it opens a terminal and immediately prompts me for a password. It should be using the SSH key I tried to connect with.

Is there any config required ( `~/.ssh/config` or `~/.config/1Password/ssh/agent.toml`) to get this to work? I had hoped that 1Password would have all the information it needs just from the SSH item in the vault such that no more configuration is needed. It has the hostname, username and key.