How to add HS Transcript (from the locker) to transfer application

I have been asking this to the school and no one was able to give me an answer. There seems to be no option for me to add my hs transcript to my app from my locker (Official doccuments)! Please help

My understanding is that all transcripts must come directly from the high school or college to the office of admissions. Then the admissions office connects it to your application.