When you change your text and image in the 'Shared content' section under 'Social', you may not see your changes.
This is because Facebook is caching this content and they do not update their cache very often.
However, there is a way to force Facebook to update their cache with your new content.
First, find the address of your campaign and copy it, e.g. go.julekal.com/vnk
Then go to this page on Facebook: https://developers.facebook.com/tools/debug/
Paste the address of your campaign into the field and click 'Debug'
If your page has not been shared yet, you will get this warning – just click 'Fetch new information'
If you page already has been cached by Facebook, click the 'Scrape again' button.
The Facebook debug page will now fetch the new content from your campaign and show you a preview of what will be shared: