const web3 = new Web3(providerAddress);
const myContract = new web3.eth.Contract(abi, contractAddress);

let validate = myContract.methods.validateAuthentication(accountAddress,'data',1).call();

validate.then(res=>{
            console.log('res',res) //returns false, successfully
        })

let event1 = myContract.methods.getMoreTokens().send({from:accountAddress});

event1.then(res=>{
 //does not reach here
})

Unhandled rejection Error: Returned error: The method eth_sendTransaction does not exist/is not available
    at Object.ErrorResponse (/node_modules/web3-core-helpers/src/errors.js:29:16)
    at Object.<anonymous> (/node_modules/web3-core-requestmanager/src/index.js:137:36)
    at /node_modules/web3-providers-ws/src/index.js:76:44
    at Array.forEach (<anonymous>)
    at W3CWebSocket.WebsocketProvider.connection.onmessage (/node_modules/web3-providers-ws/src/index.js:53:36)
    at W3CWebSocket._dispatchEvent [as dispatchEvent] (/node_modules/yaeti/lib/EventTarget.js:107:17)
    at W3CWebSocket.onMessage (/node_modules/websocket/lib/W3CWebSocket.js:234:14)
    at WebSocketConnection.<anonymous> (/node_modules/websocket/lib/W3CWebSocket.js:205:19)
    at emitOne (events.js:116:13)
    at WebSocketConnection.emit (events.js:211:7)
    at WebSocketConnection.processFrame (/node_modules/websocket/lib/WebSocketConnection.js:547:26)
    at /node_modules/websocket/lib/WebSocketConnection.js:321:40
    at _combinedTickCallback (internal/process/next_tick.js:131:7)
    at process._tickCallback (internal/process/next_tick.js:180:9)