Are you using your Telus Account login or the Optik account login? There are two different logins/passwords and only the Optik one works.
The Optik app usually gives you a choice of using the Telus account login or the Optik one. The Telus one will work with the Optik app only. The Optik account is the one you set up on your PVR and the only one I've been using to access Global / CTV / Crave
See Optik account instructions: https://www.telus.com/en/bc/support/article/set-up-optik-tv-account
I am experiencing the same problem. Even when I follow all of the instructions to create an Optik TV account, when I open the app on my phone a pop-up message comes up saying that the app is no longer supported for Apple devices. It says that you can use the MyTelus sign in credentials for an account instead, but the MyTelus account sign-ins are not accepted by any other app. It's a vicious cycle and I keep going around and around. Currently there doesn't appear to be any way for Apple users to create an Optik TV account at all and I haven't been able to get any help. None of the material on the Telus website has been updated. It has been incredibly frustrating to deal with.