italki used to require that lessons be booked at least 24 hours in advance. About two weeks ago, this changed to booking at least 12 hours in advance.

Hi Elise! Have you solved your problem? You could try to sign out and then sign in. When you have problems that you don't know how to fix by yourself as well as by others, you can try to contact italki. They respond very fast. :)

maybe we can practice each other I help you chinese you help me English

What are you meaning?