Walk into the post office and purchase the postal order (a fee is charged for it).
You will be provided with a postal order on which you can state the post office to be paid at and the recipient's name.
Post it to the recipient. They can bring it to their post office and get the value
For €10 probably cheaper to do a bank transfer if you can't do Revolut.
Postal orders were issued in Ireland from 1881 until they were discontinued in late 2001 just before the change over to the Euro. The current alternative is the An PostPostal Money Order which serves an equivalent purpose.[1]
It;s just another antiquated paper payment tool. When the receipient gets it, they lodge it to their bank account and the bank treats it like a cheque and give cleared funds once An Post pay them
An Post has ended the sale of savings stamps, which will put an end to a decades-old practice of children purchasing them in schools and saving enough to make their first lodgement to a post office savings account.