Issue while sending the file as the response in node API

Question

I'm trying to send the file as response in node API.

In my front end I'm getting this error : Unexpected token H in JSON at position 0 at JSON.parse

In that error I can see the filecontent.

API Code

        res.download(path,'file.txt',(error) => {
            if(error) {
                error.status = 500
                res.json({
                        status  : error.status,
                        message : error.message,
                     })
            }

        })

Front-End

this.apiservice.downloadattachments('file.txt').subscribe(response => console.log(response))

apiservice

downloadattachments(filePath) : Observable<any> {
  let httpParams = new HttpParams()
  .set('FilePath',filePath)
  return this.http.get<any>(this.baseURL+"/download/attachments",{params : httpParams})
}