Issue with Generate Project Files

Hi guys, i have an issue with the installation of the SDK BOX IAP plug in, i’m trying to insert the In App Purchases in my project, so i’ve find this plug in, i have a problem with the installation because i have to unzip the file inside the engine folder and then i have to launch the GenerateProjectFiles script, but i have not this script in my project, How can I do ?
Thanks.

Now i’m studying from Unreal Match 3 project.