Step 1: Let your Firestick install apps from outside the Appstore
Go to Settings → My Fire TV → Developer Options. On most current Firesticks you'll see an "Install unknown apps" menu — open it and switch Downloader to ON (you can come back and do this right after step 2 if Downloader isn't installed yet). Older models show a single "Apps from Unknown Sources" switch instead; turn that on.
Don't see Developer Options at all? Amazon hides it on newer Fire OS versions. Go to Settings → My Fire TV → About, highlight your device name (e.g. "Fire TV Stick 4K") and press the select button seven times. A message confirms you're now a developer and the menu appears.
Good to know: This only allows the specific app you switch on (Downloader) to install files — it doesn't open the whole device up.







