VPN on iPhone — How do I keep the BOXED “VPN” notice in the upper right?

Hello—

When I use BitdefenderVPN on my iPad, there is a little icon that appears in the upper right at all time. It’s the letters “VPN” in a rectangle. I find this really helpful because it allows me to always be sure that VPN is on and connected. On the iPhone, on the other hand, this icon appears briefly when I connect, but then it disappears. Does anyone know of a way to keep it there permanently while VPN is connected and being used?

Thanks!