cant*

How it work? We can hear us

Sorry, I don't think it works in sandbox. It uses specific DarkRP functions.

not equipping in sandbox. This is the only file for this I have is there more?

Then you need an addon.json in the main folder that contains the other folders, this page will tell you how to format the file:
https://wiki.garrysmod.com/page/Workshop_Addon_Creation

It says addon.json isnt found

Did you modify the folder structure at all? Did you put any invalid files in any of the folders? Also, try running gmad from CMD, it's difficult to explain so it's best if you look on the internet yourself for how to do that.

for some reason, it wont accept the gma extracted folder it just closes out

No, you need to open lua files with some sort of text editor, preferably one that has a plugin for GLua (I use Atom personally). If they're in the correct folder structure in your Gmod addons folder whenever you edit them you can reset the map you're on to review your changes, you can keep the game open while editing and when you save and restart the map it'll have updated. If it was something spawnable you'd just have to respawn the entity but not in this case.

is there an addon where i can edit this ingame?

I got the file path wrong before, it should be in
/steamapps/common/GarrysMod/bin/

Don't download one, you might get a virus.

I don't have a gmad.exe ... got a download

You mean the folder containing the extracted addon? Gmad both decompiles and compiles so just drag the folder onto the executable.

Okay, but how do I create the folder itself into a gma?

I'm not sure, sorry. Perhaps you would get a useful response if you asked on the original addon, but I'm not sure. You should ask someone with Lua experience otherwise. You can decompile an addon to view its code by using a program called "gmad" which is in steamapps/garrysmod/bin, just drag and drop the .gma onto the executable and it should extract it.

how to add more channels to the radio?