About create-an-avatar-video-v2

Please let me know about the following API
https://docs.heygen.com/reference/create-an-avatar-video-v2

Is it possible to specify “ImageBackground” and “VideoBackground” as backgrounds at the same time, and compose a static image background and a video background at the same time?

We have confirmed that this is possible on the heygen console, so we are asking if it is possible to generate this in the API.

If it is possible to specify both at the same time, which layer is higher in “ImageBackground” and “VideoBackground”?

Thank you in advance.