Just a hint. Never use the search feature here at FR. It sucks. Has for years.
Ctrl-F.
A Ctrl-F Search using Pelosi shows 3 prior threads before yours concerning the letter from Trump to Pelosi.
I first saw this on Twitter from Sarah Sanders, so I searched for it on the web using whitehouse.gov extention.
That gave me the White House website. So I used the actual title on the White House website.
Copied the actual HTML from that site and displayed the URL for the .pdf version.
Will be more cautious.