Add /Edit Couriers
From Shopnix Help
How to add new Courier?
If you want to add a new courier service provider, then you need to follow below-
Go to Admin > Setup > Couriers > Add New Courier
Then you will redirect to Add Courier page, Fill the require details and click on Add button to add the courier as shown in below image
How to edit Courier details?
For editing the courier details you need to follow-
Go to Admin > Setup > Couriers
Then you will be redirected to Edit Courier page, make modification whatever you want and click on Save button as shown in below image-