@gincoin and erafjel are both correct, this is a trojak(3 groschen) from the Poznan mint (the numista reference coin is mine

), the same Iger subtype, P.91.3a (spelling POLONIAE reverse) as the pegasus auction link.
IF are the initials of Johan Firlej, the crown treasurer, and also appear on coins from the Olkusz mint.
The numista section on Poland is very good, you just need to know to look under Poland-Lithuania Commonwealth for coins after 1569, and Kingdom of Poland for earlier dates.
Edited by tdziemia
08/15/2020 12:26 pm