Issue With BankNifty Weekly Expire

Hi I am trying to place banknifty weekly expiry order through kite publisher but i am getting an error like
status error,message : no vlaid orders found in payload, data:null,error_type:input exception

Please find my input request:
KiteConnect.ready(function() {var kite = new KiteConnect('APIKEY');kite.add({'exchange': 'NFO','tradingsymbol': 'BANKNIFTY18122022800CE','quantity': 20,'transaction_type': 'BUY','order_type': 'MARKET','product': 'NRML'});kite.finished(function(status, request_token) {window.location = 'https://www.redircturl---/'+status;});kite.renderButton('#default-button');kite.link('#custom-button');});$( document ).ready(function(){document.getElementById('custom-button').click();});