The HTTP Cross-Origin-Opener-Policy (COOP) response header allows a website to control whether a new top-level document, opened using Window.open() or by navigating to a new page, is opened in the same browsing context group (BCG) or in a new browsing context group....open() , whether it is a popup, tab, window, or other context. Navigations...login page is served on a separate origin, due to password manager...