I am using Netsuite CPQ module, when I add the configured item into a salesorder from Netsuite UI, it gets added. Adding the same configuration fro SCA is showing this error : "Error adding item(s) to the Cart: Please enter a value for amount". Any leads?

Do you have pricing setup? I haven’t used CPQ but you might try to do the same thing it does via plain old NetSuite UI (assuming it’s creating a sales order) and follow the same steps to see if it gives you the same issue.