This is coin B9 from the "My First Dirties" thread at
https://goccf.com/t/149267Needs more cleaning but I wanted to check my newbie attribution attempt. I went about it in a stupid way but I think it worked. His curly beard looked familiar based on the Roman Emperors by Portrait page at Forvm and from there I looked through pictures on Wildwinds.

19mm, 1.8 gm (thin little sucker!)
I think it's this:
Gallienus, antoninianus, Rome, 260-268 AD
GALLIENVS AVG, radiate head right.
IOVI PROPVGNAT, Jupiter standing left, head right, brandishing
thunderbolt, XI in left field.
Not sure of the mint since I can't see the mark. All of the others I've found online that have the same features were from the Rome mint.