The 'by attribution' feature of the Creative Commons licence imply that you add your authorship for exported images. You can set your authorship during upload of then image to the WEB databases. Insert your name or nickname to the "author" field. Setting your mail address is optional.

To see the authorship of downloaded images look at the tool tips of the images displayed in the tool window.

Move the mouse over an image in in the pool window. If authorship is set for this image you can see the name and probably the mail address in the image window.