Installed Duckdns add-on and now cannot connect to my hassio using the app

I am running hassio on a pi3 without any issue (V0.80.20 new install)
iOS app is 1.5.0

I have just installed the DuckDNs addon as I want to be able to access outside of my home network, all is working fine with internal access however the iOS app on my iphone will not save the details at all and throws up this error

The app finds my hassio instance correctly when I am connected to my internal network via wifi but will not save/validate
if I drop off the wifi and try to use external access even after manually entering the correct url address “” it still throws the same error, I am surely missing something here but not quite sure what all /any help much appreciated.

Take a look at the beta Public Beta Testing is now open!

Thanks @Richard_Gaunt, followed this post and that fixed my issue