No button to enter code on account page

Bug Report
1

In addition to a description of the bug you are reporting, please provide:

Device Type: IPhone
Device Model: 13 pro Max
Device Operating System: 18.1.1
Diablo Immortal App Version: 3.1.5

2

I believe this option only exists on PC and Android. On iPhone, you need to go to Menu > Settings > General, make a note of your UID and then use that on the website for submitting codes.