Back before the pandemic, students would put together a full application (ED or other type, depending on college), fill in everything on the Common App that is needed, without signing or submitting, have a hard copy of everything that would be submitted, and have a meet with a Posse person at the office with all the material. I cannot remember if they simply dropped off all the material or also signed and submitted the online application at the Posse office.
They should provide that information at the parents meeting, as well as schedule meetings with Posse people for a “virtual” drop-off.
The application, though, is the same Common App that is filled by everybody applying to that college.