Using this option system will send the another rate for the Shopify shipping checkout.
This option is use for the Standard Delivery and Express Delivery.
In this screenshot as you can see I set the “Send another rate” which is increase the rate by $20 from the normal rate.
Here after surcharge, exclude product and all condition executed and final rate is $90 as a shipping for standard.
Now System add addition $20 and send $110 for express delivery like that.