Every time I try to use the app it says the sim in my iPhone 8 isn’t an Optus sim. This is a lie, I’ve been with Optus for many years and have kept the same number. It’s beyond a joke. I have deleted the app and redownloaded the app using my phone data not wifi and still asks for a 4 digit code to then get told I can’t cant get access and yes I’ve tried turning my phone on and off.
No.. I get the password but it won’t let me passed that point it pops up saying my sim isn’t Optus when it is, it’s not a new sim either I’ve had it for months and had this number for years.
Have you tried a new SIM? You can pick up a replacement in an Optus Store.
If that doesn't work, Tech Support will need to raise an IT Case for investigation, jump into Live Chat once you've tried a new SIM and they can open a fault ticket.