You don't actually need either a business website or an email domain (or a business, really). I went ahead and set the Hilton for Business account up in order to qualify for the Hilton credit on my Business Platinum card - the terms for the credit say you qualify once you set up the account and receive an email back from Hilton that it is set up, which I got without filling in a website; I do have an email domain name but that was an optional item that would restrict access to the account to people using an email account from the domain.
Just paid $50 towards my MFs at The Quin using the Business Platinum card - I'll report back when I get the credit. This is a nice replacement for the Adobe benefit, which now ends on 6/30/25 according to the website - I wasn't using that one anyway. It's a bit better for my usage than the Dell one, also ending 6/30/25 - I had used that one for a couple of little nice to have things but paying MFs is a better option. Hopefully they add another benefit to replace the one of those this doesn't cover.