When you are adding Images, instead of uploading an image from your local computer you can use an external link to add images. If you have an image uploaded anywhere online with a public link you can use that public link to add image. The link must be public which doesn't require any account login to view and should not be masked. Ideally if the image is uploaded on any website you can get the image link by right clicking and opening the image link on a new tab.
Note: An external image link would contain a .png, .jpg etc extension at the end. Here is an example of an external image link: http://funnelify.com/fe/images/logo-light.png