NotForProfit experts, how do you print Tax Receipts in NS? Is this a customization?

You can get a Sales Invoice with Tax information as a standard. You can get this report from Transactions/ Sales menu or reports.   However, if you want the Tax receipts to be in different format then NS has an option to customise the report as per require format and name it as “Tax Receipt”.   Hope above answers your query.

Thanks @Deep Patel!