JSFiddle - React, Tailwind, and code Playground

HTML

<button type="button" class="themeChanger" data-theme-value="grid2" value="Grid">
   data-theme-value                
</button>

<button type="button" class="themeChanger" data-themeValue="grid" value="Grid">
   data-themeValue
</button>

JavaScript

$(".themeChanger").click(function () { 
    alert($(this).attr("data-themeValue")); 
    alert($(this).data("themeValue")); 
});