In New UX, the page access flows over from the model access given to each user in the Anaplan Model. There's no need to set page access separately for each user as of now. This is the error messaged displayed when a user tried to access a card to which they do not have access
@Anilkumarch, all existing permissions are respected from the model, eg selective access and module level access. You can also assign page level access via the page options menu on a page in the New UX. This uses the existing roles in the model the page is pointing at. If a user has no access to any pages in the app then they won't see the app. You can see a short video of how this works in the link below:
While, the roles, selective access and DCA as defined in the model is all respected in the NUX. You can also limit access to the pages while in the design/ edit mode of the page through the page options> Restrict Users.
This will only be enabled if you have some roles defined in the model as this will be role specific and you will have to select a role.
Let me know if you have require any more information