Requests a pre-shared key for TLS-PSK.
func onTLSPSK(connectionID: Int64, identity: String, psk: inout String, ciphersuite: inout String)
The class fires this event to report that a client has requested a TLS-PSK negotiation. ConnectionId indicates the unique connection ID that requested the PSK handshake.
Use Identity to look up for the corresponding pre-shared key in the server's database, then assign the key to the PSK parameter. If TLS 1.3 PSK is used, you will also need to assign the Ciphersuite parameter with the ciphersuite associated with that identity and their key.