Confused and distraught

My counselor recently told me I should submit my transcripts from the university I dual enrolled at to all the schools I applied to. However, I have no idea how to do this and my counselor doesn’t either. Most application portals have an area for submitting additional materials, but a lot of them say that transcripts should not be submitted there. Does anyone know, if most schools require dual enrollment transcripts to be sent? How do I go about sending them? Does it matter if they are official or unofficial? (I am particularly looking at Columbia right now and cannot find any information on this)

Thank you!!!!