What is the make and model of the TV?
If the TV uses the Android operating system (and some other Smart TV OS - but support varies), it is really easy - just call up the video on your phone / tablet / computer, and then click the "Cast" icon (a rectangle with a sort of WiFi symbol in the bottom left corner); select your TV from the list of devices that is presented as the target, and the video will play on the TV.
"Simples!"
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