UPenn additional letter of reccomendation

I want to submit an additional letter of recommendation for my transfer application to the University of Pennsylvania, but I can’t figure out how. The Penn admissions website says to send it through common app, but common app only allows the two required instructor recommendations.

I called Penn and they said that I could either submit it as a coach’s recommendation or have the recommender send it to Penn directly.

I can’t find a place to submit a coach’s recommendation, does anyone know where/what this is?

Also, if I can’t find it, is my recommender supposed to send it directly to the main Penn admissions email or a specialized address?