EMR provides a software WebUI entry to access the native UIs of components. It is required to authenticate access requests. The username is "root", and the default password is the one you entered when creating the cluster. You can reset the native UI password in the EMR console if you forgot it. This document describes how to do so.
The password must contain 8 to 16 characters with at least three of the following character types: uppercase letters, lowercase letters, numbers, and special symbols (! @ # % ^ *). The first character cannot be a special symbol.