I think strange that you require a public URL to tranfert the audio file... That could be very complex for developers to first store audio file on a cloud provider, allow public access and then pass it to Hooho service.
Why not allowing to transfer data directly using an multipart/form-data or a base64 string?
Hello matt-api, indeed it is something we plan to improve. The particularity is that depending on the technology used, it is necessary that the file be hosted on a specific platform. For example, AWS only accepts files hosted on AWS.