I cannot process Return for any item without referring to the original Sales Invoice

I cannot get this to work. I dont see the “Is Return/Credit Note” option when making a new Sales invoice.
Why would that be? I think this feature has been integrated in all latest versions of ERPNext. I am on a paid version of ERP Next ver 10.1.51 (master).

Please HELP, since I need this urgently, we do frequent returns and exchange.

You’ll have to do it as journal entry type credit note. We face the same issue. There’s no return/credit note on a new sales invoice until version 11.