Please use the following code to make the full version visible:

< a href="LINK">< img src="LINK">< /img>< center>Click for full resolution< /center>< /a>

Remove the 5 blanks after "<" in the code and put your link into the 2 places "LINK"

The attribution should be something like this:

Barks by Schamangerbert is used under a CC-BY-SA-4.0 licence. Modifications to this photo include cropping (or what you have done).