When the plugin is installed correctly and you've made the integration you will have a button called Visma Addo in your Super Office.
In order to upload a document for signing click on the Document tab, which you find in the bottom of the screen. Here, you get the opportunity to upload a document as you would normally do. Next, you will have to click More and make sure you choose Sign with Addo before sending out the document.
When this is done correctly, you will be able to see the new transaction within the Visma Addo tab. Here, you will also be able to see and follow the status of the transaction.