How to make it so that when trying to parse, python does not output an empty string?

Question

Python

When trying to parse the initial price in steam, the python outputs an empty string

import requests
import lxml.html

def parse(url):
    api = requests.get(url)
    tree = lxml.html.document_fromstring(api.text)
    text_original = tree.xpath('//*[@id="market_commodity_forsale"]/span[2]')
    print(text_original)

parse('https://steamcommunity.com/market/listings/730/Shattered%20Web%20Case')

Answer 1

There is absolutely no content in the block with ID market_commodity_forsale.
So either ask valve to add the data you need there, or look in the requests as they appear there