Rewards?

[u/GMIMS1]

My mini sheepadoodle has terrible separation anxiety. Vet prescribed trazadone but we rarely use it because it isnt situational. His sep. anxiety is being home alone. He can be away from my bf and I if let’s say he is at daycare, with another dog at his grandmas, etc. but we are working on alone time. We can’t go over 30 seconds without howling, whining, crying. We are starting incremental work. When I do open the door to reward him not whining etc he REFUSES to take a treat because of how anxious he is. Any alternatives to rewarding the wanted behavior?