fix - free product transaction save

apps/warehouse/pos/api/v2/serializers.py

@@ -199,10 +199,13 @@ class InventoryQuotaSaleTransactionSerializer(serializers.ModelSerializer):
                 gov_product = item_data.pop('gov_product', None)
                 free_product = item_data.pop('free_product', None)
 
-                distribution_id = item_data.pop('quota_distribution')
+                distribution_id = item_data.pop(
+                    'quota_distribution'
+                ) if 'quota_distribution' in item_data.keys() else None
+
                 distribution = QuotaDistribution.objects.filter(
                     id=distribution_id
-                ).first() if 'quota_distribution' in item_data.keys() else None
+                ).first() if distribution_id else None
 
                 quota_stat_id = item_data.pop('quota_stat')
                 quota_stat = OrganizationQuotaStats.objects.get(id=quota_stat_id)
@@ -210,7 +213,7 @@ class InventoryQuotaSaleTransactionSerializer(serializers.ModelSerializer):
                 # create item for transaction
                 item = warehouse_models.InventoryQuotaSaleItem.objects.create(
                     transaction=transaction,
-                    quota_distribution=distribution,
+                    **{'quota_distribution': distribution} if distribution else {},
                     quota_stat=quota_stat,
                     gov_product=Product.objects.get(
                         id=gov_product