JSFiddle - React, Tailwind, and code Playground

HTML

<select class="btn dropdown-toggle" ONCHANGE="swapContent(this)">
    
    <option value= 'Prva'>Kategorija</option>
    <option value =2>2</option>
    <option value='Treca'>3</option>
    <option>4</option>
    <option>5</option>
    </select>

JavaScript

function swapContent(that) {
	if(that==2)
			alert(that.value);
    
}