Merge pull request #12738 from rohitwaghchaure/hotfix_pos_issue

[Fix] Pay button not working in pos
diff --git a/erpnext/selling/page/point_of_sale/point_of_sale.js b/erpnext/selling/page/point_of_sale/point_of_sale.js
index f5bc6c2..357475d 100644
--- a/erpnext/selling/page/point_of_sale/point_of_sale.js
+++ b/erpnext/selling/page/point_of_sale/point_of_sale.js
@@ -1268,7 +1268,7 @@
 		this.disable_highlight = disable_highlight;
 		this.reset_btns = reset_btns;
 		this.del_btn = del_btn;
-		this.disable_btns = disable_btns;
+		this.disable_btns = disable_btns || [];
 		this.make_dom();
 		this.bind_events();
 		this.value = '';