Does that mean that all businesses will be shut down at 11:00?

That's what a curfew is.

Business close but people still free to be out as they please. Not sure how that applies to food and beverage within hotel. For now probably a good idea and to me mainly the locals are out late.

LINK
Pretty much spells it out .

So how would visitors have access to an app or receive a QR code?

They would have to show their Vaccination card hard copy.