Calling Powerschool API from inside powerschool Authentication

Question

I'm trying to call a API that I created (plugin) in Powerschool from a new Powerschool page but I don't want to authenticate by oauth because I should be able to send the request without any authentication because I'm already authenticated in the PS console but I don't know how to do it... I tested with the permission_mapping xml file, but it doesn't work, also I tried sending in the request the session cookie that I get when login but that didn't work either, maybe I doing something wrong, if somebody here can help me I will appreciate it. Note: sorry I can't to give more details about the codes.