It is not possible to store staff attendance in the same way as for students, with an attendance mark for a time period. This is because there isn't the same legal requirement to report on specific attendance sessions as for students, such as for the school census.
It is also not possible to sync with a third party, such as Inventry, to pull this data into Arbor because there is nowhere in Arbor for this data to be stored.
Staff are presumed to be in school (during their logged working periods) unless an absence has been recorded for them. You can see a list of those staff members who aren't in school from School > All Staff > Absences.