Roku APP says HBO MAX is installed. When I try to watch HBO MAX on Roku TV it says to choose a plan and then pay for it with my ROKU Pin. When I try to pay on the HBO MAX app on ROKU TV it won’t accept my pin. I went to the ROKU APP and updated my payment info and changed the pin last night and HBO MAX cannot verify my information.
If you just updated your Roku PIN try restarting your Roku device by using "System restart" under Settings->System or Settings->System->Power.
You may find it easier to subscribe to HBO Max directly (not through Roku):
https://www.hbomax.com/subscribe/plan-picker