JSFiddle - React, Tailwind, and code Playground
HTML
<select id="myselect" data-native-menu="false">
<option>1</option>
<option>2</option>
<option>3</option>
<option>4</option>
<option>5</option>
<option>6</option>
</select>
<div id="keyOpen" style="background-color: blue;"></div>
<div id="keyClose"></div>
JavaScript
$( "#myselect" ).selectmenu( "refresh" );
$(document).keyup(function(e){
if(e.which >= 48 && e.which <= 57){
$("#myselect").selectmenu( "open" );//this should open the select
$("#keyOpen").empty().text(e.which);
}else if(e.which >= 58 && e.which <= 90){
$("#myselect").selectmenu( "close" );//this should close the select
$("#keyClose").empty().text(e.which);
}
});