One of the reasons why you cannot find your order might be that you have signed in with Apple ID when you created your account on the Ticket Portal.
Please bear in mind that all notifications regarding your orders and tickets should be forwarded by Apple to the email address associated with your Apple account. In some cases, it may happen that you receive the notifications with a slight delay. Please make sure that you also check your junk/spam folder(s).
If you selected to hide your email address when signing in with Apple ID, your real email address will be hidden and your account will be associated to an auto-generated Apple ID email address, with the domain @privaterelay.appleid.com. You will still receive our notifications at the email address associated with your Apple account.
IMPORTANT: when you login into the Ticket Portal to view the details of the purchased tickets, you need to sign in again with Apple ID.
Where can I find the auto-generated Apple ID email address with the domain @privaterelay.appleid.com?
Login into UEFA.com and check the Ticketing email address: