Add a helpful message or alert to the date/time selection page on your online bookings page to inform clients about something while are searching for their ideal appointment date and time.
For example, you may want to inform clients that they can call or email you if they can not find a suitable time from your online booking page. You may also want to tell clients to contact your business if they are feeling unwell and give you notice before they arrive.
Go to Settings, then Online bookings and add text to the date/time selection section.
In online bookings time/date selection info will display here: