Hi @Ivolutio,
So, take a look at the following post on how you normally use the asset.ready() callback and the this.app.assets.load() method to start loading an asset:
But since you are doing the loading yourself, and not using the internal resource loaders, I’d say you only need to replace this line:
asset.loaded = true;
With this:
asset.fire('loaded', asset);
So basically you replicate what Playcanvas does internally, firing the event yourself.