If you want learner agency, you also want intrinsic motivation.
And that means your classroom practice, and therefore its culture, needs to be one where:
Kids can do things they’re interested in.
Imagination is present.
You are attentive and responsive.
Purpose is given time to emerge.
Kids get the time they need to do things well.
There’s lots of time for low-stakes exploration and experimentation.
Sharing, collaboration, and interaction are always possible.