Get the content of the web page through python according to Firebug's post, but it can't be displayed correctly?

I want to get some ip
http://spys.one/en/free-proxy.

of this website.

because if I click servers per page to change to 100 or 50, there will be more ip in the table. I check that Firebug, should be a post request, and then I replace headers and params with what is shown in Firebug.

but the result is still 30 in a table. Instead of 50. What"s wrong?
I dropped some comments in header because it seems to make mistakes all the time, but I don"t think the problem lies here

import requests
import json

headers = {"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
           "Accept-Encoding": "gzip, deflate",
           "Accept-Language": "en-US,en;q=0.5",
           "Connection": "keep-alive",
           -sharp "Content - Length": 29
           "Content - Type": "application / x - www - form - urlencoded",
           -sharp "Cookie": {"_ga": "GA1.2.1327775775.1542557446", "_gid": "GA1.2.1490822828.1542557446"},
            "Host": "spys.one",
            "Origin": "http: // spys.one",
            "Referer": "http: // spys.one / en / free - proxy - list /",
          -sharp "Upgrade - Insecure - Requests": 1,
            "User - Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36"
           }
url = "http://spys.one/en/free-proxy-list/"

params = {"Form Data": {"xpp": 1, "xf1": 0, "xf2": 0, "xf4": 0, "xf5": 0}}

res = requests.post(url, params=params, headers=headers)