To enable Developer Options on an Amazon Firestick, follow these steps:
Turn on your Firestick and go to the Home screen.
Navigate to Settings: Scroll to the far right of the Home screen and select Settings (the gear icon).
Go to My Fire TV: Scroll down in the Settings menu and select My Fire TV.
Enable Developer Options: Scroll down and select About.
Now, highlight Fire TV Stick (or Fire TV) and then press the select button 7 times. You will see a
notification pop up at the bottom saying, “You are now a developer!”
Access Developer Options: Go back to the previous screen, and now you will see Developer Options available in the menu.
Once in Developer Options, you can enable options like ADB Debugging and Apps from Unknown