In relation to my comment on Ronald’s answer, this is how I closed the popup in the URL redirector. The ACT_ClosePage microflow simply needs to cal th Close Current Page action after a time of your choosing.
Use the URLRedirector app for that: https://appstore.home.mendix.com/link/app/113/Mendix/URL-Redirector
You can set the target there to a new browser page instead of the same browser page.
Regards,
Ronald