functions.php

function my_theme_remove_optins() {
    if ( is_user_logged_in() ) {
        wp_enqueue_script( 'remove-optin', 'remove-optin.js', array( 'jquery' ), wp_get_theme()->get( 'Version' ) );
    } elseif ( wp_script_is( 'remove-optin', 'enqueued' ) ) {
        // This check is needed to show the Optin.
        wp_dequeue_script( 'remove-optin' );
    }
}
add_action( 'wp_enqueue_scripts', 'my_theme_remove_optins' );