Add to homescreen changes in Chrome 68 - Pete LePage
Pete LePage writes about important changes to Add to Homescreen in Chrome Add to Home Screen changes If your site meets the add to home screen criteria, Chrome will no longer show the add to home screen banner. Instead, you’re in control over when and how to prompt the user. To prompt the user, listen for the beforeinstallprompt event, then, save the event and add a button or other UI element to your app to indicate it can be installed.