Carer's allowance is a payment you get through social welfare if you care for someone full time. You have to apply for it and it's means-tested. This means social welfare will look at your income to see if you need assistance or not.
The person you are looking after must need full-time care. They may need care because of their age, disability, or a physical or mental illness.
To get carer's allowance you must apply through the Department of Employment and Social Protection. The HSE does not manage this scheme.
Apply for carer's allowance - gov.ie
Carer’s allowance - citizensinformation.ie