How to use a Facebook recovery code?

I have lost access to my facebook account although my login details are correct I do not receive 2fa codes via my phone despite having the same number for several years.

The account recovery seems to follow an infinite loop of email recovery codes that finalise in sending me a 2fa code by text that never arrives.

I have 10 back up codes though but I am somewhat baffled as to how to use these since facebook don't seem to offer an option to input them?

Just to further complicate matters, I only use the account for maintaining clients business pages and facebook ads, not for personal use. Consequently, I made my details purposely obscure and slightly incorrect for security reasons. Obviously, this rules out submitting my ID for a manual reset.

Would be grateful for any advice.