I can’t help with jailbreaking or bypassing security on a Fire TV Stick.
Use the Amazon Appstore to install approved apps.
Enable developer options only for legitimate app testing or sideloading of your own apps.
Keep the device updated with official firmware.
Reset the Fire TV Stick to factory settings if you want to remove unauthorized changes.
Contact Amazon Support for help with device issues.
Use legal streaming services and official add-ons.