HTTP request - Content-Disposition attachment variable

Hi,

I have a request I want to test like this:

### Upload File
@filename = "small-test.xlsx"
 POST http://localhost:8000/v1/file/upload/
Accept: application/json
Authorization: Bearer ABCD
Content-Type: multipart/form-data; boundary=WebAppBoundary

--WebAppBoundary
Content-Disposition: attachment; filename={{filename}} name="file"

< /path/to/{{filename}}

--WebAppBoundary
Content-Disposition: form-data; name="payer_id"
Content-Type: application/json

1
--WebAppBoundary--

The variable is recognised in the  Content-Disposition header

However it's not recognised in the file path section

< /home/glance/Documents/Claims/{{filename}}

Any way I can get this working?

Thanks