Keep getting missing client_secret when using Twitch API (OIDC Authorization Code Flow)

API
4

as per OIDC Authorization - Bad Request - PHP

Check your headers are right.

Personally I’m running (for nodeJS Express/Request)

    var code = req.query.code ? req.query.code : false;

        request.post({
            url: 'https://api.twitch.tv/api/oauth2/token'
                + '?client_id=' + config.twitch.client
                + '&client_secret=' + config.twitch.secret
                + '&code=' + code
                + '&grant_type=authorization_code'
                + '&redirect_uri=' + config.twitch.redirect,
            headers: {
                'Accept': 'application/json'
            },
            gzip: true,
            json: true
        }, function(e, r, b) {
            if (e) {
                console.log(e);

                return;
            } else if (r.statusCode == 200) {