I cannot enter authorization info on my iphone

I go to settings in the app on my iphone and click on authorize and it will not let me enter any information. No keyboard pops up.

I have books downloaded to may computer and they are supposed to automatically show up on the iphone with the same authorization. Nothing is showing up - not the sample book or the ones I purchased.

Is there a problem with this app and iPhone 6? Do I uninstall and reinstall the app?

I tried refreshing the app and I restarted the phone.

Thanks for your help.

Jirina