How to fetch the buying amount/ Cost of a particular invoice?

I need to include the buying amount/ Cost for the invoice while sending the notification, how can i do that? Kindly help.

Two parts to your solution:

How do you find/fetch the cost?

Answer: Only applicable if you have perpetual inventory turned on. Go to the corresponding stock transaction - Sales Invoice with Update Stock checked or Delivery Note and see how much got booked to the Expense Account (Usually Cost of Goods Sold). That’s the cost.

How to include that in the notification?

Not sure. Maybe somebody else can answer this question.

Hope this helps.