This is how I do it with ATT (replace phone)
1) Apple Store app iOS
2) have X in favorites (as far as it will go)
3) My carrier info for the check (phone#, zip, and last 4 social) are already there, so when I click it, it checks, and brings me to the plan selections.
4) It asks me if I want to downpay (which I don't to save time 😀 ), I click save, and it brings me back to the previous plan select page, where I click continue at the top.
5) it sends the thing to 'The bag'.
6) I click on that and there's the nice Apple Pay button, which I click
7) then I'm on another page with is the final page with shipping options and 'place order'
All this should be filled in. You don't need to input anything, anywhere. So it should take you about 10 to 15 seconds
Also, I'm totally unsure about how to refresh the App, which is a crucial stage. I'm getting conflicting advise. Some people say you just need to change apps, but I'm very unclear about it. All this above is useless if you're late out of the gate.
Could somebody explain in detail what to do?