production page access control

so I have set up this thing (1st pic) on my CF page, and this will show me login code page (2nd pic). But it seems that this can be only enabled for preview deployments. Let's say i got a lot of preview deployments, like a.my-app.pages.dev b.my-app.pages.dev c.my-app.pages.dev and so on. so an attempt to access these pages will always show you this login code page, which is cool. but my problem is that I need to set this up for my production page as well, on my-app.pages.dev. But it seems that there is no such functionality for this? Or is it only because i am on a free plan, so that specific feature is not visible to me?