With Bulkly, you can easily use images hosted elsewhere. Most of the time you just need to use the full URL to the image. For example, https://bulk.ly/wp-content/uploads/2020/01/linkedin-showcase-pages-1024x536.png.
However, with Dropbox hosted images you will need to be sure your URLs follow this format.
According to https://help.dropbox.com/files-folders/share/force-download,you need to have "?raw=1" at the end of your image URL. For example, https://www.dropbox.com/s/42glhyad7byugt3/2020-02-06%2017.54.45.jpg?raw=1
And the image will be like this:
