Mapping Dropbox URL in HTTP Request Node: Need Assistance

I have an HTTP request node, and I need to map a Dropbox URL from the previous step to the node. I can see the Dropbox node pop up as a selection, but when I click the down-arrow, the only “field” I see is a generic “Output” field. But I only need the URL. So I need to “drill down” further into this Output, like you can in Make.com. See attachment.