If you created the project with CUBA Studio or CUBA CLI, it already has CUBA Gradle plugin configured. You do not need install task, it builds and installs the project into your local maven repository to make it available for other projects, you do not need it now.
You can zip the project in two ways:
First:
Open terminal inside your project directory.
Print gradlew zipProject (./gradlew zipProject if you use linux or mac) in the terminal.
Press Enter.
Second:
In CUBA Studio find Gradle button on right panel. Click on it, Gradle toolbar will appear.
Inside the toolbar, there it your project tree. Expand it, find Task -> other -> zipProject.
Double click on zipProject.
Both approaches will generate zip archive in projects root.
Thanks a lot. I was able to start the application in the browser.
From the main menu, CUBA-> Start Application Server
(The console says then: “Server started at http://localhost:8080/app” and I was able to log in.)