Screen time passcode

What is the current iOS version on your phone? You must be at iOS 13.4 or higher.

Otherwise, you'll need to erase your iPhone using your computer with iTunes and you cannot restore it from backup after you get back in. Follow the directions in this link --> If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support

You will need to figure out you Apple ID passcode. You can go to iforgot.apple.com, there it will give you steps to reset your Apple ID, and if necessary put you account in to recovery mode(this can take almost two weeks to process so make sure to do it as a last resort).

Once you figure that out you should be able to turn it off by going to screen time passcode and saying I forgot, and then it will give you the option to reset it. If that isn’t working you will need to restore your phone to remove it, but you will still need your Apple ID otherwise your phone will be activation locked.