I want to update my uploaded files meta data using flex service. Any way to do that in nodejs. Please help me it's urgent.

The sdk doesn't support it but the API behind it does so you can create a request manually and run it.

Here is a example of an ajax request that we make:

async function saveFileData(file, token, appKey) {

    return new Promise(function(resolve, reject) {

        var auth = 'Basic ' + token;

        var URL = "https://baas.kinvey.com/blob/" + appKey + "/" + file._id;

        $.ajax({

            url: URL,

            type: 'PUT',

            data: JSON.stringify(file),

            headers: {

                'content-type': 'application/json; charset=utf-8',

                'Authorization': auth,

                'X-Kinvey-API-Version': '3'

            },

            dataType: 'json',

            success: function(result) {

                resolve(result);

            },

            error: function(err) {

                reject(err);

            }

        });

    });

}