When you set a field in eDocBuilder to be an image field, the image can be either set on the field as a default image, it could be setup to allow a choice of image assets uploaded to the template, or it could be set as an image upload. There is no way to instruct an image field to load a graphic file available on a web address, like you might setup when creating an html page for a website.
But if the field is set for an image field using field scripting, then if you have a full url to a public image, the template can load images that are available on a web address by using the VB Script method for the output for the field.
These images below are available in the skinImages folder in a Pressero account. The skinImages folder exists in any Pressero account, and can be navigated to by going to Tools > File Manager from the menu in Pressero admin.
http://admin.chi.v6.pressero.com/files/subscribers/be686231-fbe3-4bea-9f91-e58ea1e60499/Skinimages/uni-earth.png
http://admin.chi.v6.pressero.com/files/subscribers/be686231-fbe3-4bea-9f91-e58ea1e60499/Skinimages/uni-moon.png
http://admin.chi.v6.pressero.com/files/subscribers/be686231-fbe3-4bea-9f91-e58ea1e60499/Skinimages/uni-mars.png
http://admin.chi.v6.pressero.com/files/subscribers/be686231-fbe3-4bea-9f91-e58ea1e60499/Skinimages/uni-jupiter.png
The field that is displaying the image in the eDocBuilder template is setup for Type of Field: Image and Data for This Field Will Come From: Static Text or Field Scripting.
This example template linked below uses a vbscript statement that allows a choice of which of the four images will show on the template when customizing. But it's not necessary to use scripting to make the image show, it just makes for an interesting example.
If just a single image needed to be shown on the field in the template, the full url address would need to be added as a string of literal text to the Field Scripting tab with VB Script chosen as the scripting language. Note that the full address to the image is enclosed in quote marks, that makes sure it is seen as literal text by eDocBuilder.
In the example template that you can
try here, the drop-down menu on the left allows for selecting a different name, that then loads a different image from the web addresses using the scripting assigned to that field. Hit Update Preview after selecting a different name on the drop-down to see the image load into the template.
The scripting that was used on the field of the template is below for reference. It reads the value selected in the drop-down field that shows on the left input area when customizing the template, and chooses a different image from the images listed above that is then displayed in the template when previewed.
ifs(inputField="Earth","http://admin.chi.v6.pressero.com/files/subscribers/be686231-fbe3-4bea-9f91-e58ea1e60499/Skinimages/uni-earth.png","") & ifs(inputField="Moon","http://admin.chi.v6.pressero.com/files/subscribers/be686231-fbe3-4bea-9f91-e58ea1e60499/Skinimages/uni-moon.png","") & ifs(inputField="Mars","http://admin.chi.v6.pressero.com/files/subscribers/be686231-fbe3-4bea-9f91-e58ea1e60499/Skinimages/uni-mars.png","") & ifs(inputField="Jupiter","http://admin.chi.v6.pressero.com/files/subscribers/be686231-fbe3-4bea-9f91-e58ea1e60499/Skinimages/uni-jupiter.png","")