Frequently Asked Questions Parents Technical Questions I got a message on my phone that says “Requires Google authentication” when I open the Zemcar App, what do I do? Go to “System Settings” then “Apps” then “All”. Scroll down to the bottom of the list to find "Zemcar" and tap on the link. Press these buttons in this order: "Force stop" and then "Clear data”. Exit “Settings” and open the Zemcar app again.