Notifications are not sent to ok mini apps. how to solve?

Question

API

We have created an application - a survey for users in ok mini apps (similar to vk mini apps).
At the beginning, we ask the user for permission to send notifications, the user agrees, but then, if possible, there is no way to send a message, the answer comes via api

{
"response": [
{
"status": false,
"user_id": 546625539582,
"error": {
"code": 1,
"description": "Notifications are disabled"
}
}
]
}

although 100% permission is available, since through the interface we can only unsubscribe from notifications.
That is, the button works, but in fact it is not possible to send a message.



How to be?