Unable to save web form

I have created a Web form

frappe.ready(function() {
// bind events here

frappe.web_form.on('flight', (field, value) => {
	frappe.call({
		method: "frappe.client.get",
		args: {
			doctype: "Airplane Flight",
			name: value // Fetch based on value entered in the field
		},
		callback: function(r) {
			if(r.message) {
				// Fetch Airport data
				frappe.web_form.set_value('source_airport_code', r.message.source_airport_code);
				frappe.web_form.set_value('destination_airport_code', r.message.destination_airport_code);
				
				// Fetch shedule and time details
				frappe.web_form.set_value('departure_date', r.message.date_of_departure);
				frappe.web_form.set_value('departure_time', r.message.time_of_departure);
				frappe.web_form.set_value('duration_of_flight', r.message.duration);
			}
		}
	});
});

})

and used this code to Fetch data from link field
Fetch data is working properly
and even its doctype also
but I am unable to save data using doctype