public function get_additional_content(): string {
		$option_key = $this->get_option_key( 'add-content' );
		$content    = tribe_get_option( $option_key, $this->get_default_additional_content() );

		// Convert linebreaks into paragraphs.
		$content = wpautop( $content );

		// @todo: Probably we want more data parsed, or maybe move the filters somewhere else as we're always gonna

		/**
		 * Allow filtering the email heading globally.
		 *
		 * @since 5.5.10
		 *
		 * @param string         $content  The email heading.
		 * @param string         $id       The email id.
		 * @param string         $template Template name.
		 * @param Email_Abstract $this     The email object.
		 */
		$content = apply_filters( 'tec_tickets_emails_additional_content', $content, $this->id, $this->template, $this );

		/**
		 * Allow filtering the email heading for Completed Order.
		 *
		 * @since 5.5.10
		 *
		 * @param string         $content  The email heading.
		 * @param string         $id       The email id.
		 * @param string         $template Template name.
		 * @param Email_Abstract $this     The email object.
		 */
		$content = apply_filters( "tec_tickets_emails_{$this->slug}_additional_content", $content, $this->id, $this->template, $this );

		return $this->format_string( $content );
	}