Why does BeautifulSoup return []?

Question

Python

import requests
from bs4 import BeautifulSoup

num = '[phone]'
responce = requests.post(f'https://phonenum.info/phone/7{num}')
soup = BeautifulSoup(responce.content, 'html.parser')
operator = soup.find_all("div", class_="paramValue", id="mnp_ported_operator")

print(f'ОПЕРАТОР: {operator}')

Answer 1

import requests
from bs4 import BeautifulSoup

num = '79031234567'
responce = requests.post(f'https://phonenum.info/phone/{num}')
soup = BeautifulSoup(responce.content, 'html.parser')
operator = soup.find_all("div", class_="paramValue", id="mnp_ported_operator")

print(f'ОПЕРАТОР: {operator[0].text}')

I understand the conclusion of the operator from the site is necessary?