Use the One Tap JavaScript API

If you'd prefer, you can use only JavaScript code to trigger the One Tap prompt.

In JavaScript, you first need to call the initialize() method to set up configurations, and then call the prompt() method to display the prompt UI. See the following code snippet:

<script>
  window.onload = function () {
    google.accounts.id.initialize({
      client_id: 'YOUR_GOOGLE_CLIENT_ID',
      callback: handleCredentialResponse
    });
    google.accounts.id.prompt();
  }
</script>

You can provide a callback function to the prompt() method to receive prompt UI status notifications. See the following code snippet:

<script>
  window.onload = function () {
    google.accounts.id.initialize({
      client_id: 'YOUR_GOOGLE_CLIENT_ID',
      callback: handleCredentialResponse
    });
    google.accounts.id.prompt((notification) => {
        if (notification.isNotDisplayed() || notification.isSkippedMoment()) {
            // try next provider if OneTap is not displayed or skipped
        }
    });
  }
</script>