It was requested to be said during the SOTU. It was said during the Easter presser later on. It's probably the weakest Q proof, but anons go nuts over it even though that's not the first, or last time @POTUS has said it.
If @POTUS had said it during the SOTU, it would absolutely have been a proof, but plausible deniability and all that.
Anon, there are hundreds of other examples of Q proofs. Just saying that since the request was made for SOTU, and @POTUS used it during the Easter address (a phrase @POTUS has used before and after being elected) it's not a proof. I even argued with Q over this.
I'm a huge supporter of this place and the movement, but this proof has always pestered the shit out of me; especially as badly as anons doted all over it.
At any rate, to answer your question, @POTUS has used it many times:
https://www.metabunk.org/threads/debunked-tip-top-as-a-qanon-clue-from-trump-hes-said-it-before.9921/
Just saying; other proofs have been much stronger.