Gets the URL of the new page that was added by a Blocks app, when installed on a site.
The getAppPageUrl()
function returns a Promise that resolves to a string with a URL of the new page that was added by a Blocks app, when a widget is installed on a site as a new page.
Learn more about app and widget installation settings.
The ID of the page on which the widget is added, as defined in the Installation Settings.