Mysterious religious iCloud AppleID appearing when I try to Turn ON or Turn OFF FindMyMac. Have I been hacked?

Hello there! This is my first post.

Some years ago, my husband bought me a Mac (a 2019 i9 Intel Macbook Pro) when I needed a computer upgrade. I believe he purchased it from the Apple store.

Recently, while trying to erase my laptop (I wish to trade it in) I noticed a strange phenomenon:

• I open Erase Assistant.
• Everything proceeds as usual.
• I'm asked to 'Turn Off FindMyMac' by entering an AppleID password
• This apple ID is NOT mine. It honestly has me worried that I've been hacked, and I am worried because I did attempt to put in my own password.

It is "appleid@churchbcc.***" which looks rather suspicious. When I try to search it up, all that appears is the Church of British Columbia.

What should I do? How can I erase my Mac? (Do I enter Recovery Mode & use the Disc Assistant? Will this problem continue?) I've attempted to turn ON Find My Mac (my mac is and has been connected to my iCloud for years) but it simply asks me again for this same religious password. Should I change my AppleID password?

[Edited by Moderator]