You can delete pages from the dashboard, under the three dots menu located to the right of the page listing.
Note that with this, you will only find the option to delete a page next to pages that you started in the app with us with the 'Create New' button.
This option is not presented next to pages imported to us. Instead, you'll find the 'Revert Import' button, which is functionally similar to delete, in that it will remove the page from our dashboard, but won't remove the same page on the eCommerce platform.