Yakov Volkov might have been a priest in Petropavlovsk-Kamchatsky around 1800 or slightly before. The Irkutsk bishop who appointed or sent him might have been Beniamin Bagranskii (1789-1814). The "traveling" or "expedition" church founded by Bering had already been destroyed and rebuilt.
Is there a Church reference that might identify him?
Glenn Farris in "So Far From Home" (2012) named Yakov as a priest and as the father of Osip Volkov. His source is uncited. Perhaps the only primary reference to the elder Volkov in the Latin script is in the Santa Cruz Mission sacramental registers, where Marion Pokriots found it for her essay, "Branciforte's Russian Alcalde."