Keybinding configuration example from the manual doesn't work

Nyxt Configuration Questions
1

In the Nyxt manual in the “Keybinding configuration” section, there is this example:

(define-configuration base-mode
  "Note the :import part of the define-keyscheme-map.
It re-uses the other keymap (in this case, the one that was slot value before
the configuration) and merely adds/modifies it."
  ((keyscheme-map
    (define-keyscheme-map "my-base" (list :import %slot-value%)
                          keyscheme:vi-normal
                          (list "g b"
                                (lambda-command switch-buffer*
                                    nil
                                  (switch-buffer :current-is-last-p
                                                 t)))))))

When I copy this in my config.lisp and start Nyxt, I get only a white window and this error in the terminal output:

  Package KEYSCHEME does not exist.

    Line: 8, Column: -1

This similar example works for me:
Change keybinding

So I guess, the example in the manual should be updated to:

(define-configuration base-mode
  "Note the :import part of the define-keyscheme-map.
It re-uses the other keymap (in this case, the one that was slot value before
the configuration) and merely adds/modifies it."
  ((keyscheme-map
    (keymaps:define-keyscheme-map "my-base" (list :import %slot-value%)
                          nyxt/keyscheme:vi-normal
                          (list "g b"
                                (lambda-command switch-buffer*
                                    nil
                                  (switch-buffer :current-is-last-p
                                                 t)))))))

(The difference is keymaps:define-keyscheme-map instead of define-keyscheme-map and nyxt/keyscheme:vi-normal instead of keyscheme:vi-normal.)

This way, the error is gone and Nyxt opens as usual. But the g b keybinding still doesn’t do anything.