Either Alexius II (1297- 1330) or Basil (1332-1330). Search
on either "Trebizond Alexius II" or "Trebizond Basil" at acsearch
.info to see various varieties defined by mint marks
etc. https://www.acsearch.info/search.html?term=trebizond+basil&category=1-2&en=1&de=1&fr=1&it=1&es=1&ot=1&images=1&thesaurus=1&order=1¤cy=usd&company=Retowski Die Münzen der Komnenen von Trapezunt
is the standard
reference for the coinage of Trebizond.
I think it might be Alexius II (1297- 1330) but due to poor
strike on your coin I cannot see enough of the detail to be certain https://www.acsearch.info/search.html?id=35335Poor quality
engraving, worn dies, and poor
strikes are characteristics of these coins making specific id more problematic than usual.