"An epitaph" is the word you want. (Or sometimes "an inscription.")

The word you want is "epitaph." An "inscription" is anything carved into stone, any stone. An "epitaph" is a short phrase or two about the person's life. The word "epitaph" refers to the words themselves. "Before he died, he told us what he wanted for his epitaph, and we are going to have it inscribed on his monument." In Gloucester, MA there is a place with about thirty boulders. The boulders have inscriptions on them. The inscriptions say things like "HELP MOTHER" and "KEEP OUT OF DEBT." These are examples of inscriptions, but they are not epitaphs. Thomas Jefferson's epitaph "Here lies Thomas Jefferson, author of the Declaration of Independence, and of the Statutes establishing religious toleration in the Commonwealth of Virginia." That's a "normal" kind of epitaph. For less famous people, an epitaph might say something like "Beloved husband of Mary Turner, and a friend to all." Or it might be a standard phrase like "Rest in peace" or "Gone, but not forgotten."

Usually it is cut into stone, so often called an inscription. . The wording is called an epitaph https://en.wikipedia.org/wiki/Epitaph An epitaph (from Ancient Greek ἐπιτάφιος (epitáphios) 'a funeral oration'; from ἐπι- (epi-) 'at, over', and τάφος (táphos) 'tomb')[1][2] is a short text honoring a deceased person. Strictly speaking, it refers to text that is inscribed on a tombstone or plaque, but it may also be used in a figurative sense. Some epitaphs are specified by the person themselves before their death, while others are chosen by those responsible for the burial. An epitaph may be written in prose or in poem verse; poets have been known to compose their own epitaphs prior to their death.[citation needed]