Can’t speak for Xi’an but I can confirm that Forbidden City in Beijing does accept foreign passports which wasn’t a problem despite a lack of English speaking staff - a bit strange in such a tourist location but this is one is the type of property where everyone is well versed in using translation apps so no issue.

However, there are plenty of other issues with this property and I wouldn’t stay again personally (though the location is admittedly amazing, especially for the price): This Urcove is a “renovated” old property and it shows. The walls are paper thin so you hear EVERYTHING and everyone and the aircon is barely working so you have to open the windows for some air which gets a lot of street noise in on top. There’s even some rooms facing to the inside which we were lucky to avoid. It’s a toss up whether all this is worth the location but as I’ve said, I would not stay there again personally.