How to reset Screen Time passcode for Family Sharing without an iPhone?

My son cannot make purchases with his phone. I cannot add a new card for purchases because he does not remember the Screentime Passcode. None of the methods that I've read on the forums here will work because as soon as we try to change the Passcode...it asks for his Passcode. And we end up stuck in this cycle.

I DO have Family Sharing set up. But Apple does NOT let me change any Family Settings unless I have an iPhone or a Mac and I have NEITHER. Now, my son's phone is listed as one of my Devices and yet NONE of the notifications that Apple supposedly sends to my account appear on his iPhone. Luckily, I CAN have any codes sent to my phone number which is why I was able to set up this Community account.

That said...I still can't get anything done. We can't reset his Screentime Passcode because the option doesn't exist for us. I checked the Family Sharing via my online Apple Account but there is NO option anywhere that allows me to reset his Screentime Passcode. No matter what I try, we're trapped in a Catch 22 cycle that's basically something like, "in order to change your Screentime Passcode, you'll need to enter your Screentime Passcode".

Please help. Every time there is some issue with a password or passcode on my son's phone, it leads to this dark tunnel of wasted time with no apparent solution. And I have to say, if the only solution for this is to reset his phone to factory settings then there is something seriously messed up about this entire process. Please, please, please help...

(And now the only topic that I'm allowed to select is "Family Sharing" but I don't know if this is a Family Sharing problem or not...)

[Re-Titled by Moderator]

Original Title: Can't Reset Screentime Passcode