If you have roku tv, there are keys on the tv you may not have noticed, at the bottom of tv, in the middle where light is there tv controls underneath. It being roku tv you don't need a true roku tv remote since all roku TV's use a very old code sets found in many older cable remote, old universal remotes that date well before the roku tv's were released. As long as there is a tv menu key, and cursor pad you should be set.
You can't, you need a real remote initially. Sanyo uses the same code set as the TCL, Insignal, Jvc, Element, Haier, Hitachi, Onn, westinghouse, magnavox, and philips roku tv's, so Roku tv remote from anyone of those brands will work on your sanyo roku tv. Or go to walmart, there you can get the Roku Wifi voice remote, which once paired with your tv will control it. They also sale a very good universal remote the One-For-All urc-7935 streamer remote, its on sale for $16.88. Use the directions in section D for Tcl roku tv's. here's picture next to roku tv voice remote:
Please contact your TV's manufacturer directly to report this issue and request additional support. Each Roku TV manufacturer provides direct support and warranty services for their products running the Roku OS.