Put the express in a virtual column with “URL” type.
If you need to store the link itself, you might need to make some changes to the row after the image is uploaded like example below.
There’s another option to create the image URL
But if you like to share the image file outside of your organization, you will have to to disable “Required Image and File URL Signing” under Security > options . (If you disable the option, a person can theoretically try to read other files by changing file name.)