No, I am sorry, at the moment I can’t. However, you can go to a local registry office at any time before (or after) your wedding ceremony and have the basic paperwork to legalise your marriage or civil partnership in law.
It works in the same way that it would to register a birth or death. This can take as little as 15 minutes and should cost as little as £46 (current 2024/2025 price in West Dorset) but you can go to any registry office in the country. All you need is 2 witnesses and an appointment to get legally married and you do not need to exchange rings or vows, these can be saved for your wedding ceremony.
Please note: These basic slots at registry offices can be limited, so make sure to book one as soon as you possibly can, once you have decided to have a celebrant-led wedding. Some make it harder than others to book or may not offer the basic package but it is your right to have a basic ceremony, so please do not be put off/told you can’t.