Send to voicemail button on desk phone

[Tom]

We use Poly Edge E450 desk phones with Zoom phone, in addition to softphone. I have a user that is wanting to selectively send an incoming call to his voicemail. However, when he presses the Reject button on the desk phone, it then follows his call handling "when a call is not answered call" instructions which then forwards the call to a call queue. Anyone aware of a way to send the caller to voicemail instead of following call handling? Reject button on desk phone is basically ignore not reject.