How do you make it, so your developer product has a GUI you can click in game to buy?

I really need this for my new game i'm working on.

If you say, "Please do this yourself before posting" I don't know how to script.

If you don't know how to script at all... then why are you on this website? This is made to help people with existing scripts they are trying to create. Not make them for you.

I really don't know either I am trying to get that too, I think it's model, just type in sale something.

I really need help with this too