Not a well-worn path, but high schoolers can play professional b-ball in Europe, for example, like Luka Doncic (Real Madrid at age of 13 I think) or LaMelo Ball, who played in Lithuania, when his father pulled him from Chino Hills HS.
The “one and done” rule will exist in the 2019-2020 season, but may be changed in either the 2020-2021 or 2021-2022 seasons. Condi Rice led the commission that took a look at the problem.
But now, the NBA’s G League (minor league) will accept 18-year old high school basketball players this coming season.
https://www.nba.com/article/2018/10/18/g-league-professional-path-official-release