Q1) Is it possible to assign payment method to all pincodes together or group of pincodes?
You can do this via import option.
Go to import page. When you click the import option, you will see the option to select a payment gateway.
If the pincode already exists, Still it would update the payment method. You can try with one pincode.
Go to import page. When you click the import option, you will see the option to select a payment gateway.
If the pincode already exists, Still it would update the payment method. You can try with one pincode.