There are several ways to access the store management area: from the dashboard and from the editor.
From the dashboard
In your dashboard, find your website template, hover the mouse over the three dots, and click on Store manager:
From the editor
Expand the Online store panel on the left and click on Manage store:
NOTES:
To access e-commerce features, make sure that your website template is connected to a Business subscription
To connect a website template to a Zyro subscription, follow this guide