Install Mouse Toggle on FireTV Device

Install the Downloader application
Launch Downloader
Navigate to https://tv.aptoide.com/
Click Download button
Click the Download APK button
A prompt will display to go to settings and allow installing unknown apps
Click Settings > Install Unknown Apps > Downloader > Toggle the setting to On
Click back and toggle the ADB Debugging setting On
Click back a few times to return to the Downloader app
Click Install and then Install again
After the app installation completes click Open
Use the up arrow on the remote to select the search icon
Search for Mouse Toggle
Scroll through the results until you reach Mouse Toggle for Fire TV
Click the Install button
Once the app installation completes click Open
Make sure the Enable the Mouse Service and Auto start the mouse service on device start-up are both enabled
Reboot the FireTV device by going to Settings > My Fire TV > Restart and select Restart again to confirm
After the Fire TV device has booted back up wait a few moments and an ADB confirmation prompt should display
Check the Always allow from this computer option and click OK
At this point, you can press the Play/Pause button the Fire TV remote twice to toggle mouse mode back and forth

Install Mouse Toggle on FireTV Device 🌱