How to call function in custom button?

ERPNext
1

in py @frappe.whitelist()
def list_order(self):

#doc = frappe.get_meta('Get Data Tokopedia')
#doc.list_order = 123
frappe.msgprint("test")
print(doc)

in js
frm.add_custom_button(__(‘Get Data’), function () {
console.log( ‘test’) ;
frappe.call({
method: “custom_module.custom_module.doctype.get_data_tokopedia.get_data_tokopedia.list_order”,
doctype: ‘Get Data Tokopedia’,
callback: function(r) {

		 	}
		});
	});