When you click on the “Open Remote Support” button on the Welcome page, then click “Download Remote Support”, It gets 404 - Page Not Found for macOS On Demand Support application.
It appears that the link is looking for /customer/Remote%20Support-macos64-online.dmg, but the files are now /SimpleHelp/DEPLOY/customer/Remote%20Support-macos-online.dmg or /SimpleHelp/DEPLOY/customer/Remote%20Support-macos-intel-online.dmg