Update July 28th
The HSE and Dept of Health are currently in the process of creating and sending out digital COVID certificates to Irish citizens, either by post or email. This depends on where you received your vaccinations.
The practice has no role in this, and will be unable to help you to obtain a certificate. 
Full information about the certificate (including if you haven’t received yours) is available at
https://www.gov.ie/en/publication/3a698-eu-digital-covid-certificate/
The latest information on international travel can be found at
https://www.gov.ie/en/publication/77952-government-advice-on-international-travel/