Place the following code snippet into any pages where you want Google One Tap to be displayed:
<div id="g_id_onload" data-client_id="YOUR_GOOGLE_CLIENT_ID" data-login_uri="https://your.domain/your_login_endpoint" data-your_own_param_1_to_login="any_value" data-your_own_param_2_to_login="any_value"> </div>
data-login_uri attribute is the URI of the login endpoint of your
own web app. You can add custom data attributes, which are sent to your
login endpoint with the ID token retrieved from Google.
Do Not Cover Google One Tap
To make sure end users see all the information displayed, Google One Tap must not be covered by any other content. Otherwise, popup windows may be triggered in some cases.
Please double check your page layout and elements' z-index properties, to make sure Google One Tap is not covered by any other content at any time. The UX flow change may be triggered even when only a single pixel in the borders is covered.