SET environment variables: how to do it in Windows?

[enriLoniterp]

Hi, i'm currently trying to develop my first server with Go and i'm patiently following the tutorial on read.ME. I think everything works perfectly fine considering i've followed every single step, but when it comes to run my server something is not clear to me. In fact i've seen that the server starts with the creation of a server defining FUNCTION_TARGET variable. export is not supported on windows poweshell, so i've tested Set-Variable command. It actually worked but after go build and ``go run main.go. It gives me:

PS C:\Users\Utente\Documents\go\cmd> go run main.go
Serving function: ""2022/09/18 14:43:21 funcframework.Start: no matching function found with name: ""
exit status 1

Hope someone can help me.

Enrico