- When I click the Start button, nothing happened, upgrade failed.
Normally, when you click Start button to upgrade plan, it will pop up the Shopify fee authorization page. If that doesn't work, probably the fee page is blocked by your browser, please unblock it. Reference these articles:
- How do I disable the pop-up blocker in Google Chrome?
- How do I disable the pop-up blocker in Mozilla Firefox?
- How do I disable the pop-up blocker in Safari?
- How do I disable the pop-up blocker in Internet Explorer?
- How do I disable the pop-up blocker in Opera?
- When my store is under development status, can I use it for free?
Yes. The app is free for development store. Just need to click the Start button to upgrade for free.