How to send a query parameter to a (server side data) server action and use the output through EJS

Thank you for detailed instruction! It definitely helps to understand the mechanics of SSR in Wappler better.
Although, I want to mention some details.

You don’t have to define variables via code view (step 5).
You can define it via UI in Layout settings in “Define Template Data”, as it shown in this Docs: Sever Side Rendering with NodeJS

After that it will be possible to bind this defined variables to server data in the Page settings (App -> Server Side Data): Sever Side Rendering with NodeJS

Data will be available on both Page and Layout by the method like <%=_('yourVariableName')%>