First, please make sure you have your password correct by logging out of the desktop app at https://tv.laurenroxburgh.com/ and back in again. 


If this works then please delete the app from your mobile device and reinstall it again to make sure you have the latest version installed. 


Then log into the app using the exact same credentials that worked for you at https://tv.laurenroxburgh.com/ 


This should fix the issue for you.