This page isn't loaded over HTTPS. Screen recording only works on a secure connection. If this subdomain is new, give cPanel's AutoSSL a few minutes, then reload.
Screen sharing isn't available here. That's a platform restriction on phones and tablets — no permission prompt can unlock it. You can still record yourself on camera below. To capture your actual screen, use your device's built-in recorder (iOS: Control Center → Screen Recording · Android: Quick Settings → Screen record), then bring that clip in below.