fix: lowercase fieldnames
diff --git a/erpnext/patches/v14_0/update_subscription_details.py b/erpnext/patches/v14_0/update_subscription_details.py
index 729ac18..58ab16d 100644
--- a/erpnext/patches/v14_0/update_subscription_details.py
+++ b/erpnext/patches/v14_0/update_subscription_details.py
@@ -10,7 +10,7 @@
 		frappe.db.set_value(
 			subscription_invoice.document_type,
 			subscription_invoice.invoice,
-			"Subscription",
+			"subscription",
 			subscription_invoice.parent,
 		)