Authenticate your expert.ai NL API connection and set a variable with the bearer token in node.js / javascript

authenticate.js

var uname = "username@faketest.com";
var pass = "fakePassword";

// Get a token from the NL API by creating a promise that retrieves the token when needed.
const token = new Promise((resolve, reject) => {  //we're setting the variable 'token' to the value that is returned
    var jsonBody = { "username": uname, "password": pass };
    fetch("https://developer.expert.ai/oauth2/token", {  //send the username and password to the auth endpoint
        method: "POST",
        headers: {
            "Content-Type": "application/json; charset=utf-8"
        },
        body: JSON.stringify(jsonBody)  //get the response which contains the token text
    })
        .then((response) => response.text()) // the response from the API is in plain text
        .then((res) => resolve(res));        // resolve the promise with the value of the token returned
});