We do not host images within our application. You must host images on your own website or using a third party application. One example is Amazon Web Services, but there are also free options readily available with a quick internet search.
When adding an image to a message template or web portal program description in our application, you must include the direct link (URL) to the image in the Source field.
Here is an example from a custom receipt we created. Here we are adding our logo to the top of the message: