Hi Mark,
Currently for Callback in Genesys cloud their is no option to play a whisper tone to the agent.
So as a workaround you disable auto answer for callback interactions, so that whenever a callback interaction is targeted to an agent their will be a ring on the agent's PC and they will come to know about the interaction.
You can also try the same to implement it at queue level, to set manual answer for callbacks.
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Siddhartha Chopdar
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