Adding a new project to the Projects application is an automatic process.
Any time you purchase a fulfillment service or an InstaSite for a sub-account from the Fulfillment Store, DashClicks will automatically create and add a project for that sub-account to the Projects app. You cannot manually add a new project to this application.
When a sub-account accepts your invite, they will be able to add any third-party integrations freely within their Analytics application. You will not be able to do this on their behalf unless you purchase a fulfillment service or an InstaSite for the sub-account.
When the service is purchased, the project for that sub-account is automatically added to the Projects app. With the project created, you will then be able to add integrations on behalf of your client freely.