Request must be in writing to the FOI Body that holds the records. Requests can also be made by email.

For example: If you want records about a policy matter at the Department of Housing, Planning & Local Government, you must apply to that Department or if you want access to your medical records, you must apply to the appropriate regional FOI Officer in the HSE.

When you make a request you must:
Submit the request in writing to the FOI Body that holds the records you are looking for.

•     Specify that the request is being made under the FOI Act
•     Be clear enough so that the public body to whom the request is addressed understands what records are being requested. In cases where the public body is not clear what records are being requested, it must assist the requester to put his/her request in such a way that the records being sought can be identified.
•     When you are seeking information which is personal, you will be required to supply the appropriate identification as required by the decision maker.
•     In cases where you are seeking to access records relating to a deceased person under section 37(8), you will be required to provide additional details in order to exercise  these rights.

    https://foi.gov.ie/faqs/how-do-i-make-an-foi-request/