Hi @QED,
Flawless ( @Flawless ) informed about this us earlier! 
See here : Apple App Store Submissions will require an "account deletion" option starting June 30th, 2022
I think what you need is a button with the Delete Logged in user action. Not sure if the records that user created also has to be deleted! Maybe @Flawless can add some more information about this? 
Thank you