Sorry but you can't, Roku remotes only control Tv volume, it's up to the Tv to control the AVR by hdmi-cec, but in your case it won't work with an optical cable in use.
I know that one of the "secret menus" has, or used to have, a "control AVR" or something like that which gave access to a limited set of receivers. I've actually got an Ultra (YJ prefix on serial #) set to control my Yamaha RX-A1020 in my theater room. My projector does not support CEC.
It's been 2-3 years since I set this up but I know the ROKU remote has basic control for the receiver.
Are you just unaware that this secret menu exists/existed OR do you know that the secret menu no longer exists?
It exists and works, but the steps are not allowed to posted in forums.
I'm unaware of any rule that would prohibit posting this. Also if you knew it existed but would not post, why tell people it does not exist? That's not being helpful.
