For the first 46 minutes of the game, it's one FT for as many points that could be earned - whether it be 1 point, 2 points, or 3 points. For the last 2 minutes, it's standard rules.
https://www.slamonline.com/the-magazine/g-league-rules-242/
I think if this ever went to the NBA, it would encourage intentional fouling.
BTW, in case you were still wondering, the line "5-10 FG, 2-5 3PT, 6-8 FT" = 24 points in this way: 3 two-point FGs = 6; 2 three-point FGs = 6 (as you note, the three-point FGs are included in the overall line) and (I presume) 6 FTs = 12 points.
If we wanted the box score to be specifically clear (which we'd usually want), the FTs should be broken out into 1 point FTs, 2 point FTs, and 3 point FTs.