<a href="https://support.italki.com/hc/en-us/articles/360022945974-Rescheduling-Cancellations" target="_blank">https://support.italki.com/hc/en-us/articles/360022945974-Rescheduling-Cancellations</a>;

First, if it’s at least 24 hours before the lesson, go to the lesson detail page on italki and press the “Change date / time” button” — follow the instructions after that. If the teacher does not accept your request, the lesson will remain scheduled for the original date and time. If it’s less than 24 hours, you’ll need to coordinate with your teacher, who would be well within his rights to refuse your reschedule request.

Second, contact the teacher immediately with full details, by any and all means possible (italki, Skype, or whatever contact info you have). Discuss your request with your teacher.

You can find more information on the support page — simply enter the search term “reschedule lesson” or something like that.

Thank you!