Autoanswer on Dect
Yealink W60B is only dect which you can use for autoanswer.
You need to upload on your base station firmware from here - LINK.
You need to set up the configuration on the device web settings:
#!version:1.0.0.1
account.1.auto_external_intercom = 1
account.1.external_intercom.mute = 1
account.1.external_intercom.barge.enable = 1