How do I subscribe to a postcast by its URL iPhone Podcasts app?

I have a podcast RSS URL (copied in the clipboard) that I want to listen to in the Apple Podcasts app. On the "Listen Now" screen there's a link for "Add a show by URL" but when I tap it, nothing happens. I can't see another option to add a Podcast URL. Brand new iPhone 12 on iOS on iOS 15.1.