You can ask people to sign in before they send you a request. It is off until you switch it on, and most restaurants should think before they do.
What it covers: Table bookings, collection orders, event and catering enquiries, and WhatsApp orders — all four together. There is one switch, in Profile under Bookings, because a restaurant that wants to know who is ordering wants that for every one of them.
What it does NOT cover: Reading your menu, and building a list of dishes to show a waiter. Neither ever asks for anything. Somebody sitting at one of your tables choosing what they want is not sending you a request, and putting a sign-in in front of that would be like asking for an account before handing over a menu card.
What it costs you: Orders. Some people will not sign in, some cannot, and some simply will not bother. That is the trade: fewer requests, but every one of them attached to a person you can recognise next time. Only you can judge whether that is worth it for your restaurant — a busy takeaway and a fine-dining room usually answer differently.
How it works for the customer: One tap on "Continue with Google". No password to invent, no email to confirm, no form to fill in.
If they had already filled in your booking form when they were asked, nothing they typed is lost. The request is kept while they sign in and sent the moment they come back — they do not retype anything, and you receive it once.
What they get back: Their own list. Whenever they open your menu signed in, "Your account" in the More menu shows what they have asked you for and where it stands — waiting, confirmed, declined. It is the reason the sign-in is worth their tap, and it means fewer "did you get my booking?" messages for you.
Their list only ever shows YOUR restaurant on your page. What they ordered somewhere else is not your business and is not shown there.
Turning it off: Switch it off and everything works exactly as it did before — anonymous requests are accepted again straight away. Requests already attached to somebody stay attached.