The first option in the dropdown menu of the Websites tab is the Available websites. These are all the sites that are integrated with your Google account but are not connected to Polkadot Tiger.
For an in-depth summary on how to connect your Wordpress site to the Google Webmaster Tools, visit this website.
You have the option to search for your Wordpress site by typing in its name to the search bar.
The Available tab is also the place where you can start connecting your site to the Polkadot Tiger plugin. Depending on your Pricing Plan, you can connect more than one site to the tool.