Zorii Bliss is a human leader among the Spice Runners of Kijimi, and a former associate of Poe Dameron from the years before he joined the Resistance. Keri Russell plays her, entirely in a helmet.
Poe's past, made concrete
Her function in The Rise of Skywalker (2019) is to retroactively give Poe a criminal history — he ran spice for her crew as a teenager and left without warning. It is a late addition to the character and the film handles it briskly, but it does land one good beat: Poe's friends learning this about him in real time, and Finn enjoying it considerably.
Kijimi
The planet is a cold, cramped mountain city under First Order occupation, and Zorii's operation is the sort of organised crime that functions as de facto local government where the occupier does not bother to govern. She has no interest in the Resistance as a cause. She helps because of Poe, and because she wants off the planet.
The novel
Alex Segura's Poe Dameron: Free Fall (Disney Lucasfilm Press, 2020) is the source for most of what is actually known about her, filling in the spice-running years and giving her the surname Wynn. Her survival of Kijimi's destruction is established by her reappearance at Exegol.