If an app or feature on your device is not working, not appearing, or is restricted (grayed out), it may have been disabled using Screen Time, or by an IT administrator if you are using a device owned by an employer or educational institution.
- Read this document about using Screen Time on an iPhone, iPad, or iPod touch --> Use Screen Time on your iPhone, iPad, or iPod touch - Apple Support
Tap Settings > Screen Time > Content & Privacy > scroll to Allow Changes.
- If the device is managed (Settings > General > VPN & Device Management), contact the IT department that is doing the managing.
MZfinance may be Apple's framework for handling payments. While not harmful it is does indicate something in the system is not working properly. I would contact Apple about the meaning of the error message you are seeing.
Refer to this document for ways to contact Apple ➞ Choose your country or region - Official Apple Support
Select your country (also look for "other" regions), then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.
or:
Contact Apple for support and service by telephone ➞ Contact Apple for support and service - Apple Support