```ruby
class UsersController < ApplicationController
  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if (@user.save)
      redirect_to root_path
    else
      render :new
    end
  end

  private

  def user_params
    params.require(:user).permit(:username, :password)
  end
end
```

Update user_params to accept email from register form
user
```ruby
class UsersController < ApplicationController
  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if (@user.save)
      redirect_to root_path
    else
      render :new
    end
  end

  private

  def user_params
    params.require(:user).permit(:email, :username, :password)
  end
end
```
assistant