To set up the cron scheduler in the WooCommerce Admin panel

1. Go to the Amazon panel on the left side of the navigation bar.
2. Click on Cron Scheduler to move towards the configuration page of Amazon.
3. Once you have clicked on cron scheduler, it redirects you to the page where you will schedule a cron from the dropdown as shown in the image: 
   
4. Once you selected the auto syncing frequency from the dropdown, select the check box to start your syncing now then click on SAVE as shown in the appearing image: