Screen time passcode forgotten

I purchased a new iPhone 13 and in the process of setting it up, the screen seems to freeze on this: In the meantime, in my old phone, I am trying to erase so it can be sent back for trade in value but it is asking for my screen time passcode. I don’t recall setting one up and certainly don’t remember it. I am thinking that maybe the new phone won’t log into iCloud until I clear it out of the old phone? How do I recover the screen time passcode?