to enable selection of SO irrespective of customer,removed validation for customer
diff --git a/erpnext/stock/doctype/pick_list/pick_list.js b/erpnext/stock/doctype/pick_list/pick_list.js
index 730fd7a..ababf3d 100644
--- a/erpnext/stock/doctype/pick_list/pick_list.js
+++ b/erpnext/stock/doctype/pick_list/pick_list.js
@@ -146,10 +146,7 @@
 			customer: frm.doc.customer
 		};
 		frm.get_items_btn = frm.add_custom_button(__('Get Items'), () => {
-			if (!frm.doc.customer) {
-				frappe.msgprint(__('Please select Customer first'));
-				return;
-			}
+			
 			erpnext.utils.map_current_doc({
 				method: 'erpnext.selling.doctype.sales_order.sales_order.create_pick_list',
 				source_doctype: 'Sales Order',