Thanks for posting back on the community.
Many apologies that you're unable to sign into the Sky Movies app.
Do you get an error message when trying to sign in?
Try to enter your username and password manually as sometimes with auto-fill it can place a space at the start/end of the username.
If you try to sign into Sky Sports do you get the same issue?
Let me know how you get on
New around here? To find out more about the Community check out our Getting Started guide