Poetry Portfolio during College Apps

Greetings,
I am an upcoming senior. Although I am most likely going to major in stem, one of my greatest hobbies is writing poetry. I really want to show colleges that I have a creative and literary side. I’m wondering if colleges mostly accept creative writing portfolios as a valid supplement that may help me during admissions. If so, how can I upload one on Common Application? Because I don’t see a specific place for this purpose. Is there a specific format for portfolios?
Thank you!

You need to check each college’s website to determine: 1) if the college accepts supplements and 2) if so in what format they need to be submitted.

Unsolicited advice: Please keep in mind that admissions officer will not spend more time on your application because you send in a supplements – the application will get the same length of review. If admission officers can get the idea of what you are doing from your list of ECs then there is not need to send a supplement to prove what you have done. If you do send an supplement in to a college be certain it is of a manageable length and outstanding quality.

We are sending in supplemental materials for music related activities. For most of the schools we have checked, the supplemental materials are sent through third-party portal (such as slideroom) that is directly linked in CA. I think you definitely should showcase your portfolio if the schools you are looking at have the portal. Good luck.