Registrar and celebrant

Hi,
We aren’t getting married for ages yet (2026) but we’ve been thinking about our ceremony. We have a friend who is looking to qualify as a celebrant and if he does then we’re wanting him to marry us. Now, when we’ve looked into this he can’t do so legally, meaning we would have to marry before hand at a registry office. This isn’t something either of us wants to do, so I’m just wondering if anyone knows whether it’s possible to have him marry us but also a registrar present on the day to make everything legal.
Thanks in advance!