HTML требуется флажок
//HTML 5 Answer Requires <!doctype html> tag at begining of html file
<input type="checkbox" name="whatever you need it to be" required/>
Super Stag
//HTML 5 Answer Requires <!doctype html> tag at begining of html file
<input type="checkbox" name="whatever you need it to be" required/> <div class="p-2">
<form action="javascript: void(0)">
<div>
<input type="checkbox" name="send_newsletter" id="send_newsletter" required/>
<label for="send_newsletter">Send me your newsletter</label>
</div>
<div>
<input type="submit" name="submit" value="Submit"/>
</div>
</form>
</div>