Login User hook

Hi

I tried this hook um_user_login when a user login but it seems nothing to work.
Here’s the code what I want.

add_action( 'um_user_login', 'my_user_login', 10, 1 );
function my_user_login( $args ) { 
	do_action( 'litespeed_purge_all' ); 
}

I even tried print_r($args); exit() inside this hook to check if this is the hook I’m looking for but I think its not this hook I’m looking for.

What could be the best hook to check if the user is being logged or user logged in successfully?

Best Regards,