Video value error in add subtitle

Use gradio implement video player.

i have my video file and srt file.

    video = "myvideo.mp4"
    sub = ""
    gr.Video(value=video, valabel="Video") #is ok
    tup1 = tuple[video, sub]
    gr.Video(value=tup1, valabel="Video") #Expected type 'str | None', got 'tuple[str, str]' instead 

i dont understand Parameters indicate:
value: A path or URL for the default value that Video component is going to take. Can also be a tuple consisting of (video filepath, subtitle filepath). If a subtitle file is provided, it should be of type .srt or .vtt. Or can be callable, in which case the function will be called whenever the app loads to set the initial value of the component.

value: str
| Path
| tuple[str | Path, str | Path | None]
| Callable
| None = None,

why not use?
help me , thanks