There is no store tab in my dashboard

I want to redirect my old free wordpress blog to my new domain name and would like to purchase the “Site Redirect” upgrade.

There is no “store” tab on my dashboard for me to purchase this upgrade. The WordPress support page tells me:

“Are you leaving WordPress.com? Would you like to redirect yourblogname.wordpress.com (as well as all of your permalinks) to your new domain name? Have you recently changed your blog address and need to redirect traffic to the new name? The Site Redirect upgrade lets you do just that — and managing the redirect couldn’t be easier. Simply purchase the upgrade from the Store page in your dashboard.”