Factory Reset
How do i even do an safe factory reset iphone xr but not knowing the apple ID or the Passcode anymore?
You cannot do that with Apple Support's help. WIthout the appleID password they are impregnable to the public.
Forgettimg both could be suspicious. (I mean, you may have just found this phone on the street for example)
You will need proof of original purchase from Apple (email receipt) and serial number.
. Depending on your region, you may be able to reach them here: contact Apple Support