if the iPhone 15 plus with physical sim can be delivered to the usa

If in the US you can buy from a EU/UK Amazon, for example in Europe we can buy from a US Amazon, not sure of the contrary. But it'll cost in import taxes and duties. The warranty won't work, Apple Care+ won't work...Sorry for the UPDATES

No.

Yes.

(247493)

No. It can't.

In the EU and the UK there's a tray for a physical Sim

This is absolutely terrible advice.

Please stop.