You might have already found the answer to this but I was looking for the same thing and found the following on their Investor Blog:
Making a claim for the relief
The tax refund is not automatic and needs to be claimed by the individual.
After subscribing for shares, an investor has to wait until the company sends them a formal “Statement of Qualification” (SOQ). This is a crucial document.
This can generally take a few months as the company needs to have spent 30% of the monies received. It is only at that point that they can submit formalities to Irish Revenue, which will ultimately enable them to issue the SOQ to each investor.
It is only when an individual receives the SOQ that they can make a claim to Revenue for the refund.