No code is showing up on my ipad

Hello, I'm trying to use the instructions above to use Continuity to connect my iPad Air 2 to my iPhone 5s to see text messages on my iPad that come in on my iPhone. When I turn on 'text message forwarding' for my iPad it says, "enter the code shown on your iPad", but there is no code displayed on my iPad. Does anyone know what I'm doing wrong? Thanks!

Keith