You can use the Opt-in Thank You page settings section to add custom redirect links, scripts, and more.
The settings listed are as follows:
If your Opt-in Thankyou page is time-bound, and the page duration has expired, you can choose to redirect users to a different page when they hit the page's link.
You can enter the first few letters of the page to find it in the list and select it for redirection.
You can redirect the users to a page outside of the funnel, like a blog post or your exclusive Facebook group.
Important: The page you wish to redirect to needs to be added to your WordPress Pages.
You can even add custom styling codes to your page to modify the looks of the page to your liking.
You can insert scripts in this section to your tweak and customize your WordPress store.
Once done, click on the Save Changes button.
This was all about the settings configuration available in the Optin confirmation funnel in FunnelKit (formerly WooFunnels).