College saying I'm missing my official college transcripts?

I am so confused. I recently applied to University of Tulsa early action and they sent me a postcard in the mail saying I was missing my “official college transcripts” from my high school. I am very very confused. I’m not in college so I don’t even have any college transcripts and i applied CommonApp so they should have received my high school transcripts.

Did you take any CC classes? Then you need to submit those transcripts too.

No I haven’t taken any college classes other than AP which are at my school

No I haven’t

No guesses posted here will be better than the telephone call you make on Monday. Good luck.