How do apps do to get mac by Brightscript?

Hello, everyone, I'm a developer on other platforms, I'm starting out on Roku, I have a problem that I haven't found answers to

There are several apps on the Roku Channel that display a MAC for you to upload your playlist remotely
example apps: Lumina player, IBO player

it displays a MAC for you to use and locate the ROKU via web services.

How are you doing this through Brightscript? I looked for answers but I didn't find them

Even if you uninstall the app and install it again, the Mac keeps the same address.

Could anyone help me get this result? I am very grateful for your attention, thank you all.