How to get File size from url in android

Question

I am trying to get file size but it is not working for https URL

private fun getDownloadUrlFileSize(downloadUrl: String?): Long {
    var ret: Long = 0
    try {
        if (downloadUrl != null && !TextUtils.isEmpty(downloadUrl)) {

            var builder = Request.Builder()
            builder = builder.url(downloadUrl)
            val request = builder.build()
            val call = okHttpClient.newCall(request)
            val response = call.execute()
            Log.e("@@contentLength", response.toString())
            if (response.isSuccessful) {
                val contentLength = response.header("Content-Length")!!.length
                Log.e("@@contentLength!", contentLength.toString())
                ret = contentLength!!.toLong()

            }
        }
    } catch (ex: Exception) {
        Log.e(TAG_DOWNLOAD_MANAGER, ex.message.toString(), ex)
    } finally {
        return ret
    }
}

here is the response in Log : E/@@contentLength: Response{protocol=http/1.1, code=200, message=OK, url=https://vyas.b-cdn.net/62ed43d8c0a03/playlist.m3u8}

Please help me I appreciate every suggestion and answers thanks in advance.