In your browser, open two separate tabs, both on your PrestaShop back-office:

In the first tab, you will go to Amazon module configuration, Features tab, as below;


Tab 1

Down in Expert Mode section, you will activate Expert mode:

Note that Debug Mode is inactive. Leave it as is. This check box has the effect of activating debug mode immediately in the entire module, It only should be selected upon instruction from support.

To activate Debug Mode, when the instruction will be given to you, you will check this Debug Mode box. A message will appear, this will indicate that Debug Mode is effective:



Important: It is not indicated to save the module configuration above thus you don’t have to do it! 
Do not forget to disable Debug mode after the operations