There are two main ways to use proxies in Scrapy. You can either use it per request basis or use it with every scrapy outgoing request.

How to use proxy with a single request

proxy = 'proxy_here'
return Request(url=url, callback=self.parse, meta={"proxy": proxy})

How to use proxy with every request Go to to and update process_request method and paste following code

proxy = 'proxy_here'
request.meta['proxy'] = proxy