Respond with file download to incoming HTTP request

This simple workflow demonstrates how to get an end user's browser to download a file. It makes use of the Content-Disposition header to set a filename and control the browser behaviour. A use case could be the download of a PDF file at the end of an application process or to export data from a database without replacing the current page content in the browser. With this approach, the current page remains open and the file is simply downloaded instead: The original idea was first present here by @dickhoning in the n8n community.

Help me set up the n8n workflow "Respond with file download to incoming HTTP request" (https://n8n.io/workflows/1920). It uses: HTTP Request. Import the template JSON into my n8n instance, list every credential I need to create, and walk me through testing it.