Submit a purchase order Isn't working

“exc”: “["Traceback (most recent call last):\n File \"/home/frappe-user/frappe-bench/apps/frappe/frappe/app.py\", line 64, in application\n response = frappe.api.handle()\n File \"/home/frappe-user/frappe-bench/apps/frappe/frappe/api.py\", line 59, in handle\n return frappe.handler.handle()\n File \"/home/frappe-user/frappe-bench/apps/frappe/frappe/handler.py\", line 24, in handle\n data = execute_cmd(cmd)\n File \"/home/frappe-user/frappe-bench/apps/frappe/frappe/handler.py\", line 61, in execute_cmd\n is_whitelisted(method)\n File \"/home/frappe-user/frappe-bench/apps/frappe/frappe/handler.py\", line 83, in is_whitelisted\n raise frappe.PermissionError(‘Not Allowed, {0}’.format(method))\nfrappe.exceptions.PermissionError: Not Allowed, <module ‘frappe.desk.form.save’ from ‘/home/frappe-user/frappe-bench/apps/frappe/frappe/desk/form/save.py’>\n"]”,

"_server_messages": "[\"{\\\"message\\\": \\\"Not permitted\\\"}\"]"

}