I created that widget. There is no single replacement widget for this. It uses logic that is not supported in React
Generate a new login page using the atlas web template for login page.
Then you can use an onchange nanoflow on the user ID to make it lowercase
On user ID and password input boxes you can set Enter key press event to the same login nanoflow as the login button itself. Stuff like storing the last user ID in local storage can be done using NanoflowCommons local storage functions if necessary
There is no any fully compatible version of the Login form helper widget for Mendix 11 at present.
Since the original widget’s logic is incompatible with React-based rendering in Mendix 11, you’ll need to reimplement the helper behaviors manually (or via custom widget) in a way that is compatible.