The booking system is a having some problems with the Safari browser. The full booking matrix page may not display properly, preventing you from making bookings with it. The devloper is aware of this and hopefully a fix is not too far away. In the meantime there are still ways that you can make bookings from Apple devices.
- Use the simple screen alternative, or
- Use a different browser, eg Chrome
The simple screen was developed as an easier option to use on phones and other small screens. The booking system may default to it anyway but you can click the phone icon to force it to use the simple screen.