Disable The Events Calendar's REST API functionality.
<?php
/**
* Disable The Events Calendar's and Event Tickets' REST API functionality.
*
* The Events Calendar: Will disallow other sites running Event Aggregator from importing events from the site with the
* REST API disabled.
* Event Tickets: Will disallow using Modern Tribe's QR Code Scanner app.
*
* @link https://gist.github.com/cliffordp/37f45031be10f30e27dbba63b46bcec6
*/
add_filter( 'tribe_events_rest_api_enabled', '__return_false' );
add_filter( 'tribe_tickets_rest_api_enabled', '__return_false' );