screen time passcode

Minimum requirements to reset the ScreenTime passcode are: iPhone running iOS 13.4 or later AND knowledge of AppleID & Password that were used to set up that passcode.

Unfortunately your iPhone 6 cannot (because of hardware incompatibility) support iOS beyond 12.4.8 versions.

You have only two options:

1. Cohabit with the existing restrictions
2. Erase your device loosing all data (you can't restore data from a backup since that passcode would come back). To erase your device, follow these instructions, even if referred to a different passcode:--> If you forgot the passcode on your iPhone, or your iPhone is disabled

Regards

Giulio

In order to reset Screen Time passcode, you must be running iOS 13.4 or higher. What iPhone do you own and what is the current iOS version on it.