formatcurrency.txt

https://code.jquery.com/jquery-3.4.1.min.js
https://<web-app>.domain.com/sites/<siteurl>/SiteAssets/jquery.formatCurrency-1.4.0.min.js

$(document).ready(function () {
    $('#' + amount).formatCurrency();

    $("#" + amount).blur(function () {
        $('#' + amount).formatCurrency();
    });

});

//No currency symbol
$(document).ready(function () {
    $('#' + amount).formatCurrency({ symbol: '' });

    $("#" + amount).blur(function () {
        $('#' + amount).formatCurrency({ symbol: '' });
    });

});