functions.php

// how to get multiple redirections using DOM in Contact Form 7
// mandatory from January 2018. on_send_ok is deprecated.

// wp/wp-content/mytheme/functions.php

add_action( 'wp_footer', 'redireccion_contactform7' );
function redireccion_contactform7() {
?>
<script type="text/javascript">
document.addEventListener( 'wpcf7mailsent', function( event ) {
    if( '82' == event.detail.contactFormId ) {
        window.location.replace('https://example.com/thank-you/');
        // ga('send', 'event', 'Contact Form', 'submit' );
    }
    //if( 'XX' == event.detail.contactFormId ) {
        //window.location.replace('https://otherexample.com/thank-you/');
    //}
}, false );
</script>
<?php
}