There around the emperor text:"ANTONINUS" or VALENIANUS"……… http://www.acsearch.info/search.html?id=2658972
Yes, I also have a Gallienus but with a 'Grazing Horse' reverse, both very typical for the type: But yours seems to be Elagabalus as Ken noted.
http://www.acsearch.info/search.html?id=202131 TROAS - Alexandreia Elagabal 218-222 AE-25mm (8,52 g). Av.: belorbeerte, drapierte Büste rechts.
It's Caracalla: TROAS, Alexandria Troas. Caracalla, 198-217. Bronze (23mm, 6.86 g 1). ANTONINVS PIVS AVG Laureate, draped and cuirassed bust of Caracalla to right, seen from behind. Rev. COL AVG / TROA She-wolf to left, suckling the twins Romulus and Remus. Bellinger A287. BMC 106. Very fine. https://www.acsearch.info/search.html?id=2951960