How To Connect WooCommerce Store to Sell The Trend

Head to your store's admin area in Wordpress/WooCommerce. 

From the Left Menu go to Settings > Permalinks.  Make sure that Post Name is selected

Make sure that your .htaccess file is writable in order for these changes to work.  You can tell if your .htaccess is writable by checking at the bottom of the setting page for this message.  if it's there, follow the instructions on that message and then continue.

Next Click on WooCommerce > Settings from the left menu.   Click on the "Advanced" tab all the way at the right side.  If you don't see an Advanced Tab, but instead see a tab called API, then make sure to select the checkbox that says "Enable the REST API". Then press the Keys/Apps button in blue. If you have the Advanced tab screen, click "REST API." Keys/Apps and REST API will bring you to the same screen.

Press the Add Key button.

In the Description, type in "Sell The Trend." Make sure the user selected in the USE input box is an admin level user. Change the permissions to Read/Write. Press the Generate API key button. Here you will see your consumer key and secret. This allows Sell The Trend to connect to your store.

Go back to Sell The Trend and from Left Menu My Stores > Connect Store, select WooCommerce and enter your store URL.  Approve access once you are promoted.