fix: Error on Invoice generation

(cherry picked from commit 82255293c4eb8a9f586db083d19d63c1ea435fb9)
diff --git a/erpnext/regional/india/utils.py b/erpnext/regional/india/utils.py
index 9743c3b..fd3ec3c 100644
--- a/erpnext/regional/india/utils.py
+++ b/erpnext/regional/india/utils.py
@@ -213,7 +213,7 @@
 		tax_template_by_category = get_tax_template_based_on_category(master_doctype, company, party_details)
 
 	if tax_template_by_category:
-		party_details.get['taxes_and_charges'] = tax_template_by_category
+		party_details['taxes_and_charges'] = tax_template_by_category
 		return
 
 	if not party_details.place_of_supply: return party_details