This means Advanced shipment tracking plugin is deactivated on your store. You need to active Advanced shipment tracking plugin.
This might be if TrackShip’s read/write Rest API key has been changed on your side to just read or permissions have been revoked.
To fix this, you can delete your store connection from TrackShip dashboard and re-connect it and it should generate new API keys and fix this issue.
You may have a security plugin on your site that won’t let TrackShip to make write requests. Check the settings for it and see if you can disable this or if not, contact us and we can confirm this is the issue and provide further instructions for whitelisting TrackShip.
If it’s not a plugin causing it, it’s likely a server/hosting configuration is blocking http requests from external websites. It could be a rule that is blocking write requests, or perhaps a trailing slash redirect sending POST API requests to a 404.
You’ll need to contact your hosting company and ask to remove the block. Also, edit your .htaccess file by adding the following code above # BEGIN WordPress :