The Generate option is an optional feature that creates new simple or complex and passwords. Simple passwords use random words and numbers. Complex passwords use completely random characters (letters, numbers, and symbols).
You can tap/select Generate any number of times to choose the right password for you. You can also type over any generated characters and/or add or remove characters from the generated password.
The Generate option can also be used to create simple or complex user IDs. Simply tap/select Generate to create a new password, edit as needed, and copy the resulting value into the Name field.