JSFiddle - React, Tailwind, and code Playground

HTML

<div>
  <button id="b1" type="button">1st</button>
</div>
<svg viewBox="0 0 1240 1000">
  <g>
    <polygon class="map__1" id="pol1" points="106.75,266 4,266 4,135 106.75,135 106.75,266" data-id="1">
    </polygon>
    <polygon class="map__2" points="178.25,168.655 106.75,240 106.75,135 145.75,135 178.25,168.655" data-id="2"></polygon>
  </g>
</svg>

CSS

.map__1, .map__2 {
  stroke: #000;
  stroke-width: 5px;
  stroke-miterlimit: 10;
  fill: #6e6e6e;
}

JavaScript

let btn1 = document.getElementById("b1");
let pol1 = document.getElementById("pol1");

btn1.addEventListener("click", myFunction);

function myFunction() {
	pol1.style.stroke = "#fc0303";
}