You might be using tools that block third-party providers (like AdBlock). It’s also possible that there are some issues with your ID document (it’s not valid anymore or your image isn’t clear enough). An unstable internet connection might also be an issue.
Make sure you are not using any extensions that could block an iFrame (like AdBlock) to our identity verification provider. If so, please deactivate them or use a different browser that does not have them.