How to know if the player is blocking or not?
 

I would like to get Block status that if player is currently blocking or not.
I know there is a related api function "IsBlockActive()", but the function seems to return TRUE when the player is holding the block input, not only if they are actively blocking.

Is there other option to know the status?

Unfortunately I doubt there is any API function which will return you that the player is "blocking any damage".

Are you asking for a way to determine whether the player has blocked an attack in the current frame?