The customer authorization (provided in the link you clicked) is out of date, and does not entitle you to use the Blended Threat service.
http://track.spe.schoolmessenger.com/f/a/VyKafFstm_CXyCY6GHHbPA~~/AAAAAQA~/RgRm3HxoP0QuaHR0cHM6Ly93d3cubWlsYi5jb20vZGF5dG9uL2V2ZW50cy9jb2xsZWdlcHJlcFcHc2Nob29sbUIKZPnoSPtk4p95H1Ihc29tbWVyLmJyYWRkc0B3YXJyZW5jb3VudHllc2MuY29tWAQAAAAB