Once you created all your stories and applied a rules engine at the campaign level, you can preview how the stories flow.
1) Under your campaign go onto the format you want to preview.
2) Click on the 3 dots on the right of the format and then hit "Start Stories"
3) Now a new tab will open starting from the initial story of your campaign.
There are 2 things you want to make sure:
1) No cookies have to be stored on your browser. Therefore, we suggest copying and pasting that url in a private window in Safari.
2) All stories need to be published. For each story click on edit and under "Workflow" select "Published" instead of "Draft"
The Simulator is the tool that allows you to test dynamic creatives and the paths created with the Journey Designer and the Storyboard in a simple and effective way.
Click on the symbol 
at the right top to open the dialog window and simulate the change of context via the dropdown list.
Press 
to confirm the change of context and simulate another impression.