Embed segue option is missing in the storyboard

Question

This seems to be a very simple question, but I can not google an answer. In my storyboard I'm dragging from one view controller to another, a list of segue options is popping up but there's no Embed option there which is one I need. I tried Xcode 11 and 10 and it is missing in both. What's wrong? Ho to find it?

Answer 1

This is your UIContainerView:

and ComposeMessageViewController is embedded in it.