sprite.setDepth

sprite.setDepth sets Depth on a sprite object. It takes id and z.

sprite.setDepth(id, z)

function start() {  const id = sprite.create('/sprites/hero.png', 100, 120);  sprite.setDepth(id, 0);}

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