Can't type in Apple ID Verification Code

I restored my old iPhone 4, when I got a new phone.

I now want to just use the old iPhone 4 for the timer feature, but when I try to set it up:

I've selected my WiFi, clicked Disable Location Services, Set Up New iPhone, and Sign In With Apple ID.

I then get an Apple ID Verification Code Required. The Code pops up on my Macbook Pro, but when I select OK, on the iPhone 4, I cannot type in the six digit code and cannot proceed.

Is there any way around this, just so I can use the timer app in the phone?

Thanks for your help.