Hello mvedd. Welcome to Sony Community and thank you for your post.
Not all Internet video devices are able to link a Netflix account without the use of a computer. If a Registration Code screen appears after selecting Netflix , a computer will be required to link the Netflix account.
I am having the same problem. Tried to use the number keys on the remote but no success. A different keypad (grey background) unlike the one you showed below came up. I tried to navigate to those keypad using the arrow key but it didn't go anywhere.