I can’t get the Xfinity app to work on my iPhone

I’m trying to reopen my Xfinity account and Xfinity Mobile the one I went with help at an Xfinity store. The app kept giving me this message. Access denied, you don’t have permission to access this website. I’ve tried deleting the app and re-downloading it doing it on different Wi-Fi sites or on cellular service and it still won’t let me do it