JSFiddle - React, Tailwind, and code Playground

HTML

<label>Newspaper?</label>
        <input type="checkbox" name="nieu" onchange="change()"><br/><br/>
	<div id="nime">
	<label>How?</label>
		<select name="nime"> 
			<option value="email">Email</option>
			<option value="post">Post</option>
			<option value="beide">Both</option>
		</select>
	</div>

CSS

#nime{
    
    display:none;
}

JavaScript

function change(){
    var which = document.getElementById('nime');
    var display = window.getComputedStyle(which, null).getPropertyValue('display');
	
    if(display == 'none') {
		which.style.display = 'block';
        return;
    }
    
    if (display == 'block') {
     which.style.display = 'none';
        return;
    }
   
}