If you see the below message, You may need to check that the gateway is setup correctly in the app
When you sign in to Remote desktop is a feature that allows a school users to connect to a computer in another location, see that computer's desktop and interact with it as if it were local. Remote Desktop is useful for working at home or in remote locations in school. It gives access to printing, file share and the internet, as well as school software. on the app for the first time, it will create a entry in the app. This allows you to select the desktop to login to again in the future without having to re-enter configuration. On this entry is 3 vertical dots, tapping these dots will display a menu.
Tapping edit will show you a dialogue. Tap “Additional Options”
Tap to select “rd.ccs.northants.sch.uk”
To save the change, tap “< Additional Options”, “< Edit Desktop” and then “Save”