JSFiddle - React, Tailwind, and code Playground

HTML

<select id="mySelect"></select>

<select>
    <script type='text/javascript'>
        insert_dropdown("val2");
    </script>
</select>

<select>
    <script type='text/javascript'>
        insert_dropdown("val3");
    </script>
</select>

JavaScript

$(document).ready(function(){
var myOptions = { val1 : 'AAA', val2 : 'BBB', val3 : 'CCC'};

$.each(myOptions, function(val, text) {
    $('#mySelect').append(new Option(text,val));
});
    
    
});

//function insert_dropdown(key) {
//        alert (key);
//    }