Emergency assistance，How to create the video I need from photos using API interfaces

Hello, I have synthesized an create-a-photar based on the API interface document, but how can I use this photar to create a video using the interface。

I cannot understand the relationship between interface {v1/talking_photo.create} and interface {v1/video.generate}.
How can I obtain the {avatar_id} parameter of interface {v1/video.generate}?

How can I understand the relationship between these two interfaces?
Can I directly synthesize photos into the video I need through an API?

Eagerly looking forward to your reply