I received this reply back in 2021 for Prince Charles's 1st Birthday.
This was one of the last replies I received from Luxembourg with an real stamp. shortly after this they switched to pre-paid postage. The stamp is part of a set released in 2019 called "Rural Tourism." The stamp is created by Eugène Kalmus. The postmark says "Ech loosse mech impfen covidvaccination.lu" (I get vaccinated).
Inside if a folded card, similar to Prince Charles's Birth Reply. The front of the card features the Greater Coat of Arms of Prince Guillaume. This look to be hand drawn/painted and is the same one used on Prince Charles's birth reply.
The inside of the card features a photo of Prince Charles taken by Sophie Margue. The inside has a typed message in Luxembourgish. The text is in a pale blue color. It is easier to read in person.
The card says:
Thank you very much for your kind birthday wishes for our son, Prince Charles.We thank you from the bottom of our hearts for the well-wishes you have shown on the occasion of the first birthday of our son, Prince Charles.
