Missing html in requests response python

Question

I am trying to move to the next page till the 'next' button exists at this link 'https://www.cbp.gov/contact/find-broker-by-port/4901?page=1'. I realized that the requests response doesn't have the button in it hence BeautifulSoup cannot find it. I tried adding headers/user-agent to requests but the element still doesn't appear. As far as I can tell, there is no Javascript generating content on this page. Here is the code. What am I missing?

def second_links(second_links_list=[], page2_num=0):
  try:
    with open('port.csv', 'r') as read_obj:
      csv_reader = reader(read_obj)
      for row in csv_reader:
        row = row[-1]
        page2 = requests.get(row.format(page2_num))
        soup2 = BeautifulSoup(page2.content, 'html')
        results2 = soup2.find(id='region-content')
        table2cells = results2.find_all('td', class_='views-field views-field-title views-align-center')
        for cell in table2cells:
          cell2link = cell.find('a', href=True)
          second_links_list.append('https://www.cbp.gov'+cell2link['href'])

      next2_page = results2.find('li', class_='pager-next')
      if next2_page:
        page2_num += 1
        second_links(second_links_list, page2_num)
    return second_links_list
  except requests.exceptions.ConnectionError:
    page2.status_code = 'connection refused'

Answer 1

import requests
import pandas as pd


def main(url):
    with requests.Session() as req:
        allin = []
        for item in range(3):
            r = req.get(url.format(item))
            df = pd.read_html(r.content)[0]
            allin.append(df)
        new = pd.concat(allin)
        print(new)
        new.to_csv("data.csv", index=False)


main("https://www.cbp.gov/contact/find-broker-by-port/4901?page={}")

                                         Broker Name Broker Filer Code
0                                    AXIOM TRADE INC               BTL
1                      DE LA CRUZ CUSTOMS BROKER INC               ENM
2                          ECI CUSTOMS BROKERAGE INC               BGZ
3                                   EDWIN SEDA PEREZ               9JD
4                 EXPEDITORS INT'L (PUERTO RICO) INC               ES9
5                                     GRISEL PADILLA               MU8
6                    INTEGRITY CUSTOMS BROKERAGE LLC               9QB
7                    INTER-WORLD CUSTOMS BROKERS INC               N35
8                               JAIME MADURO SANTANA               ALA
9                                      JOSE G FLORES               256
0                                JOSE M RAMOS GARCIA               97Q
1                                    JOSE R BERMUDEZ               9HD
2                                        JUAN GARCIA               9ST
3                   JULIO CACERES DBA TRADEWORKS INC               97D
4                          JULIO RODRIGUEZ USCB CORP               EWV
5                                     MANUEL A RAMOS               G68
6                            MANUEL RAMOS-GANDIA INC               CDX
7                                   NESTOR REYES INC               508
8                               NORBERTO DAVID COLON               BLC
9                  P R INTERNATIONAL CUSTOMS BROKERS               D05
0                                      PANALPINA INC               554
1                                PEDRO L CARMONA INC               BWV
2                           PEDRO L SITIRICHE-TORRES               E9T
3  RADIX GROUP INTERNATIONAL INC DBA DHL GLOBAL F...               336
4                   RANK SHIPPING OF PUERTO RICO INC               D84
5                           RENE ORTIZ-VILLAFANE INC               438
6                         ROSA MARINA FLORES-ALVAREZ               NZ5
7                     UPS SUPPLY CHAIN SOLUTIONS INC               UPS