var removeIllegalCharacters = function(input) {
    return input
        .replace(/=/g, '')
        .replace(/\+/g, '-')
        .replace(/\//g, '_');
};

var base64object = function(input) {
    var inputWords = CryptoJS.enc.Utf8.parse(JSON.stringify(input));
    var base64 = CryptoJS.enc.Base64.stringify(inputWords);
    var output = removeIllegalCharacters(base64);
    return output;
};
var exp = Date.now() + 100;
var header = { 'alg': 'HS256', 'typ': 'JWT' };
var payload = { 'client_name': 'put_client_name_here', 'exp': exp };
var secret = 'put_secret_here';
var unsignedToken = base64object(header) + "." + base64object(payload);

var signatureHash = CryptoJS.HmacSHA256(unsignedToken, secret);
var signature = CryptoJS.enc.Base64.stringify(signatureHash);
var token = unsignedToken + '.' + signature;

pm.globals.set("jwtToken", removeIllegalCharacters(token));