2011 iMac requiring password to access MacOS Recov

[twr7cx]

I have a 2011 27" iMac that experienced a failed hard drive. I followed the iFixIt guide to open it and replaced it with an SSD. Being a new hard drive when I boot the computer it shows a flashing grey folder with a question mark (?) in it – due to no OS being installed.
I therefore followed https://support.apple.com/en-au/HT201314 to enter MacOS Recovery Mode (Command (⌘) and R). Which requests a password:

https://imgur.com/mgSYUeG

I've also tried Internet Recovery (Command (⌘) – Option (⌥) – R) and same deal.

Being a brand new hard drive I'm surprised by this – I assume it's a BIOS password or something like that? I don't seem to know the password, computer was purchased used some time ago. Is there anything I can do?

 

[Razzerman]

Hey there,

Looks like a firmware password, and it also looks like you'll have to take it to an apple centre, according to this article.