How to send notifications using the SendMass method (the server responds with "Service is temporary unavailable")?

Question

Classmates

We try to call sendMass - the server responds with error code 2 and "SERVICE : Service is temporary unavailable". At the same time, the updateMask method works normally (without an error). We searched in the wiki - it is written that you can ask for rights through a ticket in Jira, selecting the necessary privileges there. But in the ticket itself there are no such fields (for choosing privileges).
Can you suggest what's wrong?
Maybe it's just that they haven't been moderated yet and the method will become available after?
Application - ok.ru/game/1240425984

Answer 1

In the case of this answer, there is approximately 99% error when calling the method. Could you post the code, maybe we'll see where the problem is.