First of all, the Fibaro’s should reset automatically, but if you remove the battery so silence the noise this will probably not happen.
I cannot test this as I have no alarm, but the solution should be to activate the green menu item from the Fibaro smoke detector. This menu item will send the current status to Homey, so should reset the alarm.
Last but not least, what you could try (and should probably do anyway after smoke detection) is the self test. If taking out the battery was wat caused this, this is a required procedure after placing a battery. I would be very surprised if either of those would not reset the alarm in Homey.
Both procedures are described in the manual better than I ever could.
