Pipe request and response with express.js #1631

Hi, I'm using express.js with request/request-promis. I have endpoint where I use pipe like this

req.pipe(request('http://mysite.com/doodle.png')).pipe(resp)

I'm trying to rewrite this endpoint to node-fetch, but I don't know how to pipe the request with this package. Do you have tip, how can I do it?