Error attach data to Retool Email in workflow

Hello there,

I’m building a workflow to send data wich is collected in a mobile app via mail.
I’m trying to do this in a workflow as I have to generate the csv file I want to send at first.
The last step is a Retool Email component where I’m trying to use the fx-Attachment.

The giving structure is following:

grafik

I tried several ways, as you can see in the pictures:

grafik grafik

But none of them worked, I get following error again and again:
{"data":null,"error":{"error":true,"message":"Use File Input component to upload a file and ensure file is uploaded before query is fired.","isRetoolSystemError":false,"queryExecutionMetadata":{"estimatedResponseSizeBytes":147,"resourceTimeTakenMs":97,"isPreview":false,"resourceType":"retoolEmail","lastReceivedFromResourceAt":1726203840907},"data":{}}}

Am I missing something? Is there any other way?
This is the relevant part of my workflow:

Best regards
Florian