What is the entity variable I will use in my template

I have created a custom entity with name Order Number
I have created an entity screen for it.
In another entity screen called view orders
I have add tcket lister widget
However Im not sure what variable I should put it to display the selected Order Number in the ticket
What I have tried didnt work
Order No:{Order Number}

Ticket Lister will only work for tickets not orders. For orders you need to use the Task Editor widget. Here is a tutorial to get you started.