Here is a ASP.NET code to use VdoCipher API. You need to simply put in the right client_secret_key and the correct video_id ( the phrase in caps in both files ). https://gist.github.com/vibhavsinha/8029efcf0b66016f8040 The code should work out of the box after extracting inside PHP running server and replacing secret_key and video_id. The structure of annotation JSON is described in the link : Add text to videos with watermark For other API and details, check out documentation or contact us directly at info@vdocipher.com.