Realtime Firebase Database how can do it?

Question

[Vabots]

W/PersistentConnection: pc_0 - Detected invalid AppCheck token. Reconnecting (2 attempts remaining)
W/PersistentConnection: pc_0 - Detected invalid AppCheck token. Reconnecting (1 attempts remaining)
W/PersistentConnection: pc_0 - Detected invalid AppCheck token. Reconnecting (0 attempts remaining)
W/PersistentConnection: pc_0 - Firebase Database connection was forcefully killed by the server. Will not attempt reconnect. Reason: Invalid appcheck token

Help me please, i don't understand, what it is.