You won’t have to do anything other than agree with your therapist when you will start and when you will end the break and why. They will process the request for you and you can corroborate it through an automatic confirmation message in the chat.
In addition, once the break starts and ends, you will receive automatic messages in the chat. And if you now look in your Subscription section of the Settings menu, you will see that your resubscription date has changed.