cptui_register_shortcode()

function my_custom_cptui_shortcode() {
    cptui_register_shortcode( 'my_custom_shortcode' );
    cptui_register_shortcode( 'my_custom_page_shortcode' );
    cptui_register_shortcode( 'my_custom_single_post_shortcode' );
}
add_action( 'cptuiext_loaded', 'my_custom_cptui_shortcode' );