Per current design, it will not work. 

Please check below Support Article for a similar issue:

https://community.pega.com/support/support-articles/actions-event-are-not-triggered-selecting-autocomplete

Thanks for responding.  The link is referring to a different issue, where they want to trigger an action based on a selection from Auto-complete.  In my case, I don't want to trigger an action from selection.  I just want to trigger one when they press Enter in the field after they type in a value. 

I could still use some help with this if anyone has some insight into it.

Thanks.

Could you please share configuration details how you have done

There is an OOB field to enter the phone number in the CTI toolbar that is an Auto-Complete.  I tried to add a simple  Enter action that runs an activity, but that event (Enter) is not being triggered.  

Thanks.

i think you have to write js for this requirement.