Cannot enable iCloud encryption on new iPhone due to old iPhone PIN

I recently went back to iphone after some years of using android phones. I’m using the original account I’ve set up those years ago. My old iphone went to trash long ago and I do not remember its PIN. I still have access to the same email and phone number I used back then. Now I cannot enable iCloud encryption features as it asks me for PINs of both the current iphone and the old one. „Devices” category in my account settings only show the new iPhone.