After connecting your WooCommerce store and not being able to verify the connection or send any products, check the store credentials by clicking the Gear icon and then Edit:
If they show empty like the image below:
Head out to your WP Admin and go to:
Settings -> Permalinks
Look for Common Settings and check Post name as your URL structure then click Save Changes.
and finally, just re-connect your WooCommerce Store
Thanks for reading and have a good one