Just to make sure:
1. You’re using test version of the plugin (that seems to be correct).
2. You’re using latest version of Subscriptions addon (1.4.5 at the moment).
3. You have created a plan with trial period (e.g. Trial Period is not zero).
4. You assigned this plan to your payment button.
I’ve did exactly the same on my test site and here’s what is shows: desertfox.top/miniserv/cleanwp/asp-products/subs-with-trial/