When you go to Upload content you will see a list of already uploaded content, with a button on each item to remove it from the media library.

To add new content, click on the Add button, selecting the desired file from your computer. You will now see a thumbnail of the selected content, along with two new buttons: Start and Cancel.

Clicking on Start will start the upload of the new content. The content will then be available in Advertisim Manager’s media library for future uploads.