The composer where you create messages sent by an automation doesn’t offer the menu, so there is no input help for wrap formatting.
In general, I am not good at remembering the right keys. So usually if I want to use wrap, for example, to add an icon like I just did above, I take a look at the topic on Meta (Discourse Icon), copy the example, paste it into my composer, and change the name of the icon. I also do that for Placeholder Forms, Reply Template, and User Field Prompt.
Pasting those examples into the RTE results in them being escaped, so they don’t work 
So the only way I found to put, for example, a user field prompt into that field was to type it manually, while I prefer to start with the example from the topic as a template.
If the menu was available when creating an automation, there would be at least some support on how to create those. Having the theme components register templates you can select in that menu would be the icing on the cake. Currently, it seems easiest to copy an example.
You didn’t ask for details on that, but maybe you can still help. How do I use the wrap option in the plus menu while I am using the markdown editor to add the icon wrap? The syntax is [wrap=icon id=circle-plus][/wrap], so I thought I would do this:
That results in
[wrap =icon id=circle-plus]
Wrap content
[/wrap]
which doesn’t work. I don’t mean the placeholder for content. My problem is the space between wrap and =icon that breaks it.