This question raises two issues.
First, in normal circumstances, people are required to present themselves in person at an office of the National Driver Licensing Service (NDLS) when renewing or replacing their driving licences. However, where a person is out of the country for a period for study or work purposes, they may apply to renew or replace their licence by post, without the requirement to appear in person at the NDLS.
The second issue is that of residence. Under EU law, Member States issue driving licences to those normally resident in their jurisdiction. As I have indicated, a person may be normally resident in a Member State even if they are living abroad temporarily for work or study purposes. However, if a person has taken up permanent residence in another country they are not eligible to be issued with an Irish driving licence.