sprite.setPhysicsVelocity

sprite.setPhysicsVelocity sets PhysicsVelocity on a sprite object. It takes id, vx and vy.

sprite.setPhysicsVelocity(id, vx, vy)

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

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