Around 6 minutes. Sets from 2018 onward.
Both Samsung Tizen and LG webOS carry compatible players in their own app stores, so no sideloading is needed.
Samsung
Press Home, go to Apps, and search for the player named in your welcome email.
Install it and open it. Note the device MAC address it displays.
Enter your credentials, or register the MAC address at the URL shown, depending on which player you have.
LG
Press Home, open the LG Content Store, and search for the player.
Install, open, and enter your credentials on the setup screen.
Older TVs
Sets from before roughly 2018 often cannot install current players, and where they can, performance is usually poor. A Fire Stick or a Formuler box is a better answer than fighting an old TV — both cost less than the time you will spend on it.
If it does not work
App missing from the store — your TV is on an older firmware. Check Settings → Support → Software Update.
Picture stutters on 4K — try 1080p first. Many smart TV chipsets cannot decode 4K streams smoothly even when the panel is 4K.
