Where can I find the 6 digit verification code on my iphone.

I'm trying to reset my appleId password, and I get a message on my iPhone but I swiped it away before I could read it. Where can I find it?

(I know I can just do it again, but if I don't have way to write it down then when the reset fails I'm not sure I remembered the 6-digits correctly and I have to start all over again...it doesn't seem to be an sms message, so where is it?).