Cannot add mashup in Page Layout

Hi,

I cannot find an option to assign a mashup to a screen in page layout. I can do this in the master layout but not on the page layout. I tried multiple SAP blogs and get mixed answers. Some say its not possible to assign via page layouts. Some say it is possible. This blog says its possible. https://answers.sap.com/questions/11272817/sap-cloud-for-customer--mashups-authorization-base.html

Any thoughts on whether this is really possible or not with page layouts?

Thank you

Julius