sprite.setCollideBits

sprite.setCollideBits sets CollideBits on a sprite object. It takes id and bits.

sprite.setCollideBits(id, bits)

function start() {  const id = sprite.create('/sprites/hero.png', 100, 120);  sprite.setCollideBits(id, 1);}

sprite.create is there to give the call something to act on; sprite.setCollideBits is the line that matters. The code sits in start(), which the engine calls once, when the entity spawns.