Select the image you want to upload using the select image button or by pasting an image using CTRL + V. This will upload the image and place it into the image box. You can then scale and transform the image as necessary, with the watermark being added automatically when it renders. When you are done editing the image, select the render image button to export the image, then save image to download the image that can then be pasted into Rinax. You may also right click and copy image to paste into Rinax that way.