Append data to front of array in json body of api

I have {{}} which returns a partial url. I need to add "" to the front of this in the body of an api call. How would I do this? I tried "" + {{}} and this {{" +}}

Its hard to answer this without seeing the input/output. You can see it if you click on the input box inside the API creator a smaller tool tip should pop up below it showing what the "Output" will be. Just play around until you get it how you like it.

I would try removing quotes and + I don't recall using JavaScript inside my API calls besides when fetching data.{{}}

(Remove the / if its already inside the DisplayImageURL obviously)

can this be done with transformer?

@nroeder yep!

You should be able to build the string in a transformer as well and pass the value to the URL field:

As Steven mentioned you should also be able to enter it into the field directly as well: