If your site has enough traffic, you should be able to see the first Heatmaps half an hour later of starting the experiment. If, on the other hand, the tested page has less traffic, then it's possible you have to wait a little bit longer; we simply had no chance to collect any data!

Still, if you don't see any data, you may want to keep in mind that Nelio A/B Testing is not enabled for admin users.