Hyde here from Shopify. Good question!
The carrier calculated shipping that comes free with your annual plan needs to be applied manually by us. What I can do is send you an email to the email address you've used to post to this forum, and if you reply to that email and it is the email you used to set up your store I will be able to access the store and activate that for you.
Alternatively, you can reach out to our live support following the links below and one of our support agents will be more than happy to do that for you!
I hope that helps, let me know which option you prefer.
All the best, Hyde.