If you must use 1809, isolate the machine from the internet or use it only in a controlled offline environment. For daily drivers, consider Windows 10 22H2 or Windows 11.
to open Developer Tools, enable mobile device emulation (toggle the phone/tablet icon), and refresh the page. This "tricks" the site into showing direct ISO download links for older versions instead of the Media Creation Tool. Media Creation Tool windows 10 pro version 1809 64bit iso download top
Once you have the genuine ISO, you can install Windows 10 Pro Version 1809 64-bit. If you must use 1809, isolate the machine