Use Google Chrome or the Chromium web browser. This requires being a little bit familiar with the developer tools of your web browser.
The developer console of the web browser reports:
getCurrentPosition() and watchPosition() are deprecated on insecure origins, and support will be removed in the future. You should consider switching your application to a secure origin, such as HTTPS.
See https://goo.gl/rStTGz for more details how to fix this.