Seamless User Experience: Maintaining Domain Consistency in a SaaS Website with Webflow and Cloudways Hosting

I have SaaS website with the main domain hosted on webflow [www.example1.com] and a separate domain for admin hosted on Cloudways [www.example2.com]. How can I ensure that users always remain on [www.example1.com], even when they click on the login/register option and navigate to the admin section hosted on [www.example2.com] ?