How do I change screen time passcode if I don’t know the passcode and it doesn’t give me the option forgot my passcode question

If you have forgotten your Screen Time passcode

Use this link to reset your passcode If you forgot your Screen Time passcode - Apple Support

If you are unable to reset Screen Time passcode from the this-> link then, you will need a computer. If you don't have one, borrow from a friend.

Forgot? Click below to reset…

Click->If you forgot the passcode for your iPhone, iPad, or iPod touch, or your ...

Regarding your data, If…

1. You have an iCloud or iTunes backup, I am sorry there is no use of a backup because if you restore from your backup your Screen Time Passcode will be back.