Can I trade my iPhone 12 Pro for an iPhone 12 Pro Max?

Hi, I would like to know if I can trade or upgrade my Iphone 12 pro for the Iphome 12 pro max and if it will cost me and how much would it cost me? The phone is basically brand new and the battery is still at a 100%.

I bought it without a plan just unlocked.

I am coming in May for a mini vacation so please let me know.

[Edited by Moderator]