Entity or Code to Confirm Samba Share Has Started

I have a button on my dashboard which toggles an input_boolean helper, which in turn, toggles Samba Share On and Off. This saves a lot of keystrokes to manually turn Samba Share on and off as I keep it off by default.

Samba Share takes a while to Start.

Is there an entity or code that I can use to confirm that Samba Share has successfully started that I can use to drive the status of the button ie. I want the button to show status = on, only when Samba Share has started rather than on when I turn the input_boolean on. Tried different searches for this but came up with no hits.

Appreciate any help, many thanks!