I am trying to add a picture to a private message on this forum. When I click on the picture icon, it asks for the URL. I have no idea what the URL is for a picture on my iphone. Can someone help me with this?
So, there is no URL associated with the photo on your phone.
A URL relates to the web address of a photo on a photo hosting website like Flicker for instance.
Here is an example of a url: