How tot use 2 factor autentification on admin login?

Hello, i have only one admin account and do not use users. I enabled 2 factor, get this qr code photo and downloaded it on desktop, i saved the long recovery code. Now i try to log in with this option and it asks me on: OTP PIN
what is that? How can i et it? when i download some “qr code reader app” in phone and scan that picture it just give me some url of my website but no otp pin

See here