Pre-Order

I recently preordered an iPhone XS Max as a new AT&T customer, and I want to get the order number, but the issue is I did not receive an email with confirmation of purchase, nor did I receive an AT&T Account Number (I finally found out I have to activate the phone). My question is how do I receive the confirmation number with no order number. I saw it the order number once but didn't think to write it down (my fault) HELP ME OUT PLEASE!