myTv+ app returns error code 100 when running on Android TV box

I have installed an app called myTv+ (https://mytv-plus.com/mytvws/) for Samsung A7 and it worked fine. I tried to install it on the Android TV box (MX9 Pro 4K) but it's simply not working, just getting "Error Code: ". I contacted the developer he said this app is designed only for the smartphone and "Error Code: " means that your Android is rooted. I noticed SuperSU on my Android TV box, I went for a full unrooting, yet the app still shows "Error Code: ". Is there any way I can force the app to work with the Android TV box?