Hi tweekat,
Thanks for getting back to us with the additional information. From Settings > Screen Time > Content & Privacy Restrictions > Allowed Apps, I would like to have you confirm Wallet is turned on.
Here's more information about how you can allow access to built-in apps and features using Content & Privacy Restrictions in Screen Time:
Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support
After that, go to Settings > General > Profiles. You'll also want to check that there are no profiles installed that will prevent access to Wallet & Apple Pay. If you need to delete a profile, here's how to do so:
How to delete an app that has a configuration profile on your iPhone, iPad, or iPod touch - Apple Support
If Wallet & Apple Pay is still missing in Settings, I suggest reaching out to Apple Support:
Apple - Support - Product Selection
Take care.