[FIOS] Streaming Cinemax Using Roku Ultra

I subscribe to and stream HBO, Starz, Showtime, and Epix. My provider is Frontier Communications Fios (Seattle). I also subscribe to Cinemax but can't seem to find a way to stream MaxGo. I am not sure it matters but my TV is a 2016 LG Oled model and my Roku Ultra is what I use to stream. I am not sure this even belongs on this site but if does and you can help me, please do.