How to tile a texture in https://threejs.org/editor/?

What's the correct way to tile a texture in https://threejs.org/editor/ ?I've created a plane with a material called m1 and tried to edit the material script to:

function update( event ) {  m1.wrapS = texture.wrapT = THREE.RepeatWrapping;  m1.repeat.set( 2, 2 );}

but nothing happens.