Google 'Change of Address' 301 redirect from homepage

We're trying to use Google 'Change of Address' system in Search Console.
(A company name change forced a new website update) Both sites (OLD/NEW) are in Squarespace.

Search Console is asking for a 301 redirect from the OLD site Homepage! I've tried a few things in URL mappings, and reached out to Squarespace support, but they tell me you can't redirect a LIVE homepage!

Fingers crossed someone has found a solution to this... However, no one seems to be asking this question online anywhere. I can't be the first to hit this problem, can I?!

Thanks in advance, even if it's a lot of people telling me it's not possible. 🙂