By default, the plugin allows its functionalities both to registered users and to unauthenticated users. However, you can choose to limit wishlist use only to registered users by enabling “Enable wishlist for > Only authenticated users option in the General settings of the plugin settings dashboard.
As soon as they try to add a product to the wishlist or display Wishlist page, they will be redirected to the “My Account” page and a message will be shown that invites them to register.
When plugin functionalities are enabled also for unregistered users, it is shown a message by default, right inside the “Wishlist” page, that invites them to log in. This message can be changed in Login message for non-authenticated users field available in General settings > Multi-wishlist settings.
Use %login_anchor% placeholder to show login link; leave empty to hide.