Is It Harris’ or Harris’s?

There is a debate among some writing experts about how to use the possessive apostrophe “s” with names that end in “s” or “z,” like Kamala Harris and Tim Walz. But one expert advises going with what is simpler and thinking about bigger subjects.

Source : https://learningenglish.voanews.com/a/is-it-harris-or-harris-s-/7751232.html