It’s the same story in that it’s the same guy at different parts of the story. Lot showed his hospitality for the strangers (angels) from the mob by offering his daughters (they didn’t take him up on the offer), and his family was spared from the destruction of the city. Then later his daughters were worried their lineage would end (their mother had been turned into a pillar of salt) so when they were hiding out in a cave with their dad they got him drunk two separate nights to each have a chance to rape and impregnate themselves with him.