double check you are using the key from https://real-debrid.com/apitoken
if you are seeing RD+ in lists for videos and can play them i would assume you are good.
You can double check that everything is working by checking under torrents on the RD website and you should see the filename for the video you are pulling up on your Android TV.
The low hanging fruit will already be scooped up. You have to get creative with emphasis on it being pronounceable first and brevity second. I feel the biggest mistake that gets made is waiting for the perfect name and overlooking a good one.