Yes, Okta Secure Web Authentication Plugin is installed within your browser. It is an add-on that enables you to automatically sign into applications that would otherwise require you to manually enter your credentials.
If you're using Mozilla Firefox, press Ctrl + Shift + A key combination and you should find the plugin in the Extensions list.
On Google Chrome, you need to type chrome://extensions/ in the address bar and to press Enter.
Internet Explorer users will need to press the Alt key and to select Manage add-ons from the Tools menu.
If you're using Opera, the plugin should be listed under Page > Developer Tools > Plug-ins.
