The connection error might be due to a few reasons:
You do not have a shipment tracking plugin that is activated on your store - You must have a plugin on WooCommerce that allows you to add tracking information to orders. TrackShip is fully compatible with AST, AST PRO, WooCommerce Shipment Tracking.
You are using a shared host – most shared hosts have disabled the HTTP Authorization Header by default. To enable this option you’ll need to contact your web host and make sure they are not blocking HTTP requests from external websites
Please also edit your .htaccess file by adding the following:
RewriteEngine onRewriteCond %{HTTP:Authorization} ^(.*)RewriteRule ^(.*) - [E=HTTP_AUTHORIZATION:%1]Once you complete these steps, go back to your TrackShip account, navigate to the Stores tab, delete your store connection, and re-connect it.