addHeader( key, value )
Example
import { Httpx } from 'https://jslib.k6.io/httpx/0.1.0/index.js';
const session = new Httpx({ baseURL: 'https://quickpizza.grafana.com' });
session.addHeader('Authorization', 'token abcdef0123456789');
export default function () {
session.get('/api/ratings');
}