Ensure to copy your n8n workflow and paste it in the code block, that is in between the pairs of triple backticks, which also could be achieved by clicking </> (preformatted text) in the editor and pasting in your workflow.
```
<your workflow>
```
That implies to any JSON output you would like to share with us.
Make sure that you have removed any sensitive information from your workflow and include dummy or pinned data with it!
Nothing special is needed with webhook configuration. You can leave all the default settings for POST method. Your POST request to that webhook has to be a standard POST request with Excel file included.
On webhook node side the binary file will have a spacial location for it identified as $binary and presented in “Binary” view. For example,