Thanks for visiting the Community today, @ourmaninindia. 

I know how relevant for you to add the customer's name and SAC codes in the GSTR2 - 3. 

At the moment, you can only add SAC codes to your products and services. 

Here's how: 

1. Select Add HSN/SAC for items, then click Add a product or service.
2. Select product type Inventory/Service/Non-inventory/Bundle.
3. Enter all other necessary details, then add HSN/SAC code.

You can also add SAC codes or import SAC codes in volume for existing products. Check out this link for your reference: How to add HSN and SAC codes to your products and services.

Feel free to visit the Community again if you have additional concerns. We're always around here to help.