The button «Пригласить»is not active
There is no way to write to the patient
In the list of all patients, I do not see a patient who was at an appointment today or yesterday.
The button «Пригласить»is not active 

If the chat invitation button is not active, it means that the patient has already been invited to the chat before.
Chats are disabled 

For the availability of chats, the clinic must have an active Telemedicine agreement with MedRoket, enable the integration of the Patient and doctor Chat in the personal account of Medflex and allow the doctor access to inviting patients to chats.
There is no way to write to the patient 
- The patient has not confirmed or extended access to the chat

You will be able to write to the patient only after he has accepted the invitation or extended access to the chat.
- The patient's account has been deleted from the medical record

If you see the text«Пациент больше не использует чат», it means that the patient has deleted his account from the Medtochka application.
In the list of all patients, I do not see a patient who was at an appointment today or yesterday. 
The list of all patients includes patients only after an in-person appointment or online consultation for yesterday and today. It is possible that the patient has been booked for a service or diagnosis. In this case, you can start a chat with the patient if you add it manually by clicking «+Новый пациент».
Notifications are not coming 
Turn on notifications in the app settings.