Due to the nature of the therapy you are receiving, it is not possible to contact your therapist unless you have a pre-arranged agreement.
It may not always be beneficial for you as the client to have continuous access to your therapist. The interval between sessions is usually a necessary period for you to contemplate on the topics discussed during your sessions.
In case you would like to re-arrange your next appointment, feel free to send a message to your therapist from the 'Messages' tab on your Mindsum dashboard. When you send a message to your therapist, they get an automated notification to reply your message.
You will still need to cancel an appointment at least 24 hours prior to the appointment time. This is to make sure you do not get charged for the session you want to re-arrange.