"Contact your administrator" link

The customer we’re integrating with has the standard text on the “403 - App Not Assigned” error screen:

Sorry, you can’t access [app] because you are not assigned this app in Okta. If you’re wondering why this is happening, please contact your administrator.

However, in their implementation the text “contact your administrator” is a link. How can I make that happen in my own dev-nnn.okta.com implementation? And how can I change where this link points to?