Sotto played for the Philippines at the 2018 FIBA Under-17 World Cup in Argentina, where he averaged 16.4 points, 10.6 rebounds and 2.3 blocks per game. He led his team to 13th place, its best finish at the event. In a classification game win over Egypt, he had his best performance at the tournament, tallying 28 points, 17 rebounds and three blocks. Sotto represented the Philippines at the 2019 FIBA Under-19 World Cup in Heraklion, Greece, where his team finished in 14th place. He averaged 11.7 points and 7.9 rebounds, while tying with Ibou Dianko Badji for a tournament-high 3.1 blocks per game.