public function ping() {

		$pre = apply_filters( 'llms_rest_webhook_pre_ping', false, $this->get( 'id' ) );
		if ( false !== $pre ) {
			return $pre;
		}

		$ping = wp_safe_remote_post(
			$this->get( 'delivery_url' ),
			array(
				'user-agent' => $this->get_user_agent(),
				'body'       => sprintf( 'webhook_id=%d', $this->get( 'id' ) ),
			)
		);

		$res_code = wp_remote_retrieve_response_code( $ping );

		if ( is_wp_error( $ping ) ) {
			// Translators: %s = Error message.
			return new WP_Error( 'llms_rest_webhook_ping_unreachable', sprintf( __( 'Could not reach the delivery url: "%s".', 'lifterlms' ), $ping->get_error_message() ) );
		}

		if ( 200 !== $res_code ) {
			// Translators: %d = Response code.
			return new WP_Error( 'llms_rest_webhook_ping_not_200', sprintf( __( 'The delivery url returned the response code "%d".', 'lifterlms' ), absint( $res_code ) ) );
		}

		return true;

	}