Calling a contact from hubspot will call through nuacom.
Calling through Hubspot will also allow you to leave notes, meetings, deals and follow up emails through Hubspot while on the call.
Ensure the phone number has a extension or Nuacom and Hubspot will not recognize the call. Ireland being +353
You will get a option to call from browser this will be through the Nuacom Application and is advisable.
You must have the Nuacom extension. Found here