woocommerce_rest_authentication_error - 410 - Invalid signature

I am building an Ionic app using woocommerce API

Below is my woocommerce provider .ts file

import * as WC from 'woocommerce-api';
this.Woocommerce =  new WC({
        url: "http://myftuplad.com",
        consumerKey: "ok_d064f357304e",
        consumerSecret: "os_0e59869ac5e08",
        wpAPI: true,
        version: 'wc/v2'
        /*queryStringAuth: true,
        verify_ssl: false*/
    });

Below is checkout.ts file to place and order

this.WooCommerce.postAsync("orders", orderData.order).then((data) => {
    let response = (JSON.parse(data.body));
    console.log(response);
})

Below is the error :

code : woocommerce_rest_authentication_error 
status : 401
message : Invalid signature - provided signature does not match.

Thanks.