If the EASA Instructor you fly with is issued by the IAA then the instructor may sign the paperwork as long as the flight with them completes all requirements.
Be careful here.... a few years ago FCL.945 was a closely guarded commodity in Ireland so not all instructors could sign the paperwork.
Regardless, an hour with any EASA instructor and then send the paperwork direct to the IAA and Robert is your mothers brother. My EASA (IAA) examiners authorisation went in January but I could still do the “hour with” if necessary. PM me if you get stuck...