It's mentioned that Nakia left Wakanda for Haiti 6 years before the events of the film, and that was after the snap. On its own, this implies a 2024 setting for BP:WF, but has some wiggle room. 2025 is possible if Nakia didn't leave straight away after the snap.
But in the mid-credits scene, it's revealed she and T'Challa had a son who by his age, must've survived the snap and therefore must've been conceived in or before 2018. The son is kept a secret and is only known to a few, so it's likeliest that this was not much earlier than Infinity War. I think the likeliest series of events is probably:
2018 (before Infinity War): T'Challa and Nakia's son is conceived
2018 (after Infinity War): T'Challa is snapped, Nakia leaves for Haiti, gives birth to son
2023 (after Endgame): T'Challa returns in blip, spends time with family, but then dies from some disease
2024: Events of BP:WF, 1 year after T'Challa's death, and 6 years after Nakia's departure