Sounds like your reseller is an idiot but answer your question. It’s a random Mac generator buts so you can use with an emulator. It won’t change your Mac on your stick. You’re gonna stb Emu for that.

You IPTV requires that specific OUI (Organizational Unique Identifier) because that's the one assigned to Infomir, the company that manufactures Mag boxes. Their Stalker Middleware is designed to only work with Mag boxes, so it looks for those first 24 bits to confirm that your set top box is genuine.

Stalker STB emulators spoof this MAC address with the address of your choosing. You can literally put anything in there and it will be "safe" and "legit". Using a generator just means you won't fuck it up.

Also, the MAC address will sometimes take the place of a username and password, so the only thing identifying you on the network is your MAC address (because they are usually tied to hardware, this prevents account sharing).

if I remember your iptv provider gives you the mac address to link to your kodi. At least that's how I used to do it.

I searched out and purchased the pro STBEMU Android apk and installed that on my stick. Then you can configure with any Mac address.

You can just make up any last 6 digits/letters you want. No need for Mac generator but saves time. I like to use all numbers as it's easier to input. Still a chance the Mac generator can make a Mac that's already in use too.