I had this issue too, but you can use an app called Zank Remote to basically just use your phone as an Android TV Remote to get to the settings.
Or wait for Android 12 where this feature will be built in.
As of now there is no option to bookmark your episodes but we are going to implement simkl.com's API soon so you'll be able to track you Anime. So basically you'll have this feature on V2 of our app which will release soon.