Also make absolutely certain you are on the legitimate Roku web site. From your description, it's possible you're instead on a scam site. If you are in the US, the only correct URL is https://my.roku.com/link . You'll have to log into the site first of course. If you login doesn't work, or if you haven't been asked to log in, that's another pointer to a scam site.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Ultra (4800), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.