The login error is because the domain does not exist according to any DNS.
The supported way is to download the Office apps separately from the app store. Once downloaded, you must sign in, and that will activate Office. The install instructions are detailed below:
Install and set up Office on an iPhone or iPad with Office 365
Install and sign in to any Word, Excel, PowerPoint, or OneNote app on an iPhone or iPad for the first time
Your device must be running iOS 8.0 or later. App availability also
varies by country. Find out what's available in your country
Important
To use the extra features in the apps, you must sign in with the Microsoft account or work or school account that's
associated with your qualifying Office 365 subscription. If you have
an iPad Pro, you must also have a qualifying plan to do any type of
editing on that particular device. See What you can do in the Office apps on an iOS or Android device with an Office 365 plan.
To learn more about Office apps on the iPad Pro, see the Office blog
post Microsoft Office apps are ready for the iPad Pro.
If you haven't installed any of the Office apps on your iPhone or iPad
as yet, download one, or all of them from the Apple App Store.
Word
Excel
PowerPoint
OneNote
Once you download it, tap any Office app to open it. Swipe through the
introduction, and tap Sign In.
To use the extra features in the app, on the Sign in page, type the
personal Microsoft account or work or school account associated with
your Office 365 subscription, and then tap Next.
Source: Microsoft Office Helpdesk Article
http://cjshayward.onmicrosoft.com/
orhttp://www.onmicrosoft.com/
are a valid domains?