JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" name="group1" value="1"/>
<input type="checkbox" name="group1" value="2" />
<input type="checkbox" name="group1" value="3" />

JavaScript

$('input').change(function() {
    if ($("[name=group1]:checked").length > 0){
        
    }else{
        alert('select atleast one checkbox');
    }
});

 if ($("[name=group1]:checked").length == 0)
        alert('select atleast one checkbox');