asset.first().getUrl('transform') not working for s3 asset - Craft CMS 2.6.2980

Question

I can load the s3 image fine using the s3 base path and the craft cms filename that is saved in the craft cms database:

<img src="{{cdnUrl}}/filepath/{{entry.Image.first().filename }}" />
renders
<img src="cdn.imageurl.com/filepath/filename.jpg" />

However if I want to access the same image without the s3 base path (e.g. in order to use an image transform), I get a null.

<img src="{{entry.Image.first().getUrl('transform')}}" />
renders
<img src="" />

Any help would be appreciated!

Answer 1

Turns out you need to have the URL prefix set under the Asset Settings in order to call .getUrl()

Once I added this, my transforms began working.