fix(e-invoicing): minor calculation fixes (#24282)

diff --git a/erpnext/public/js/controllers/transaction.js b/erpnext/public/js/controllers/transaction.js
index 3bc20f8..bed9c14 100644
--- a/erpnext/public/js/controllers/transaction.js
+++ b/erpnext/public/js/controllers/transaction.js
@@ -543,6 +543,7 @@
 							company: me.frm.doc.company,
 							order_type: me.frm.doc.order_type,
 							is_pos: cint(me.frm.doc.is_pos),
+							is_return: cint(me.frm.doc.is_return),
 							is_subcontracted: me.frm.doc.is_subcontracted,
 							transaction_date: me.frm.doc.transaction_date || me.frm.doc.posting_date,
 							ignore_pricing_rule: me.frm.doc.ignore_pricing_rule,