How to use assetManager.loadBundle?

version : 3.5.2
https://docs.cocos.com/creator/manual/en/asset/bundle.html

I have referenced the document in the link in the paragraph above.

But it is returning an error. How should I write it?

error log :

Uncaught (in promise) TypeError: Cannot read properties of undefined (reading ‘length’)
at factory.ts:166:44
image



bundle load prefab must like this:

Thanks I check it again