From the navigation bar click on “Extensions” and then “Plugins”.
Here you will see the list of all plugins available for your site.
If you want to enable any plugin like Cookie then you have to select it using the checkbox and then click on “Enable” button which is at top-left corner of your page.
After enabling the plugin you will get the success message “Plugin successfully enabled”.
Similarly you can disable the plugin with “Disable” button, you just have to select the plugin and then click on “Disable”.