Welcome Paid Users
Send this right after a customer upgrades to a paid plan. It thanks them, names the new plan, and lists three things to try first, with one button into the product. Swap in your plan name and the three features that matter most on it, and link the button to the screen where customers start using them.
Loops
Send it once the upgrade is confirmed
Trigger the Workflow from the event your billing system sends when the plan change succeeds, not from a click on your pricing page. Replace the plan name, the renewal line and the three features with what the customer can now use, and link each one to the exact product screen. If you bill through Stripe, the Stripe New Customer template adds the plan, price and next bill date.