I’m not sure you want to create a new Modules object here, instead I think you want to commit the one you have passed in as the parameter.
You will also want to decide what to do after this action. You may want to use a “Show Page” action to take the user to a new page, you may want to use a “Close Page” action to close the page and go back to the previous page, or you may want to stay on the same page and use conditional visibility to show different content.
In the microflow, you already have the object. It got created when you opened the page. The object has not yet been committed to the database, and it is passed to your microflow via the parameter Modules (side note: best practice is Module instead of Modules). All that is left for you to do, is at the end of the microflow, after validation, add the commit-activity for the Modules