Greetings!
We will be doing a production deployment over the weekend, We would turn CRM and Partner Portal into Maintenance mode over the weekend.
We would like to display a custom message about the deployment and downtime in Partner Portal so that people visiting the url could get that information.
We have tried the option mentioned in https://docs.microsoft.com/en-us/powerapps/maker/portals/admin/enable-maintenance-mode

In the custom page URL, we have entered http://mayanksubtest.cf/iframe/

I am still not getting the above custom message displayed. I appreciate any pointers on how to get this right.
Thanks