JSFiddle - React, Tailwind, and code Playground

HTML

<input class="element text medium" id="test" name="name" type="text">

JavaScript

var downed = 0; 
$('#test').keydown(function () {
    downed++;
    if(downed == 2){
        var reformat = this.value.replace(/(\d{3}\s*)/g, function(match){
            console.log("match before" + match);
            if(match.match(/\s/)){return match;}
            return match + " ";
    });
    console.log(reformat);
    this.value = reformat; 
        downed = 0;
    }
});