How to extract HTTP response body from a Python without page that doesn't open?

Question

I am trying to web crawl a page that doesn't open.

To access that page, I have to go through two pages.

So I tryed that code.

from selenium import webdriver
from selenium.webdriver.ie.options import Options

Option = Options()
Option.add_argument("user-agent=Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko")
browser = webdriver.Ie(".\IEDriverServer.exe", ie_options=Option)

#open for login
browser.get(LoginURL)

#open for connect page
browser.get(PageURL)

#Page open
browser.get(TargetURL)

print(browser.text)

However, the last page is downloaded because of the following response header. content-disposition: attachment; filename="download.xls"

If I ignore the download and get the HTML source of the current page, I get the source of the previous page(PageURL), not the source of the final page I want.

The downloaded file is in 'xls' format, but when you actually open the file with notepad, it is an HTML Code.

And when I press F12 in IE environment and look at the network analysis, the HTML source I want is in the response body. I can also right-click > Copy Response Payload.

In Chrome(Edge), there is no preview in the response tab of network. So when I save as HAR with the content, I open it as Json format, there is something I want.

The location of the data I want in the saved HAR file is as follows. {} log> [] entries > {} 2 > {} response > {} content > text

In this case, is there any way I can crawl that source?

As a security policy, external access to the page is not allowed. So you can't open the pages.