Postman Get Oauth Bear Token Prescript with Username & Password

get_auth_token.js

// grab our env variables for access
var domain = pm.environment.get("domain");
var username = pm.environment.get('username');
var password = pm.environment.get('password');

// Send request to get token and set as env variabled {{authorization}}
pm.sendRequest({
    url: domain + '/api/token',
    method: 'POST',
    header: {
        'Content-Type': 'application/x-www-form-urlencoded',
    },
    body: {
        mode: 'urlencoded',
          urlencoded: [
            {key: "grant_type", value: "password", disabled: false},
            {key: "username", value: username, disabled: false},
            {key: "password", value: password, disabled: false}
        ]
    }
}, function (err, res) {
    pm.environment.set("authorization", "Bearer " + res.json().access_token);
});