JSFiddle - React, Tailwind, and code Playground

HTML

<table>
<tr><td>email1@example.com</td><td><button class="btn btn-warning edituser" value="Modifica" data-toggle="modal" data-email="email1@example.com" data-target="#myModal" title="Modifica">Modifica</button></td></tr>
<tr><td>email2@example.com</td><td><button class="btn btn-warning edituser" value="Modifica" data-toggle="modal" data-email="email2@example.com" data-target="#myModal" title="Modifica">Modifica</button></td></tr>
<tr><td>email3@example.com</td><td><button class="btn btn-warning edituser" value="Modifica" data-toggle="modal" data-email="email3@example.com" data-target="#myModal" title="Modifica">Modifica</button></td></tr>
</table>

JavaScript

$(".edituser").on("click", function(){
  var bottone = this;
  var email = $(this).attr("data-email");
  alert("Stai modificando " + email);
});