Appointment not booked
That time was not booked.
No appointment was created. Go back and choose another opening, or call and get it handled directly.
What to do next
Try a different opening.
Another visitor may have taken the time just before the request was submitted, or the scheduling connection may need attention. Either way, no appointment was created.
Go back to the calendar and choose another time. If it keeps failing, call 405-252-9691 and say the website booking page is not working.