Edit: ok your comments just made me buy a cheap android TV box

That's a terrible idea; those things all run hacked firmware from China with preinstalled malware. (There's a fairly recent Linus Tech Tips video about it if you want more info.)

Instead, you need to be buying hardware from a reputable brand and then (ideally) installing a Free Software OS on it yourself, e.g. a Raspberry Pi running LibreELEC.