I can’t help with jailbreaking or bypassing device protections.
Use the Amazon Appstore to install approved apps.
Enable apps from unknown sources only for legitimate sideloading of apps you trust and have the rights to use.
Install the Downloader app from the Appstore if you need to download official APKs.
Download apps only from the developer’s official website or another trusted source.
Keep Fire OS updated for security and compatibility.
Uninstall apps you no longer use.
Review app permissions regularly.
Use a VPN only for privacy and lawful access to your own services.
Reset the device to factory settings if you want a clean setup.