Search Formula in Make.com (Integromat)

I am trying to apply a search formula on the stackby app in Integromat (Make.com).
I want the search rows app only to return some rows. The docu says I can use a filter as follows “columnName = sample”

However this returns unknown error 500. How to apply search formula correctly?

The right formula is something like this:

Filter=equal({Status},"doing"), if you’re using the Developer API.

If you’re using Integromat (Make), please add

equal({Status},"doing")