You first need to add the application in your portal - Click the module access icon > Apps > Manage Apps > click New.
When adding a secure (HTTPS) application in the portal, you can choose to open the application within your portal’s frame or in a new tab.
Also, if you add an insecure (HTTP) application in your portal when accessing the application, the application will open in a new tab by default. You will also be notified if you’re adding an insecure application.
Applications that open in a new tab can be easily identified by the icon beside the application name as seen in the image below.