Problems with debugging

I can't get it to work. Whenever I set

debugger:
  enabled: true
  shutdown:
    close_connection: true
  twig: true

And I try to 'dump' something with twig

{{ dump(foo) }}

nothing appears in the debug bar.

Results in debug bar

Also, the debug bar only appears in the admin panel. Is this how it should be?
Or am I doing something wrong?

This is my full system.yaml file

absolute_urls: false
timezone: ''
default_locale: null
param_sep: ':'
wrapped_site: false
reverse_proxy_setup: false
force_ssl: false
custom_base_url: ''
languages:
supported: { }
include_default_lang: true
translations: true
translations_fallback: true
session_store_active: false
http_accept_language: false
override_locale: false
home:
alias: /home
hide_in_urls: true
pages:
theme: gebrdehond
order:
by: default
dir: asc
list:
count: 20
dateformat:
default: null
short: 'jS M Y'
long: 'F jS \a g:ia'
publish_dates: true
process:
markdown: true
twig: false
twig_first: false
events:
page: true
twig: true
markdown:
extra: false
auto_line_breaks: false
auto_url_links: false
escape_markup: false
special_chars:
'>': gt
'<': lt
types:

• txt
• xml
• html
• htm
• json
• rss
• atom
  append_url_extension: ''
  expires: 604800
  last_modified: false
  etag: false
  vary_accept_encoding: false
  redirect_default_route: false
  redirect_default_code: 301
  redirect_trailing_slash: true
  ignore_files:
• .DS_Store
  ignore_folders:
• .git
• .idea
  ignore_hidden: true
  url_taxonomy_filters: true
  frontmatter:
  process_twig: false
  ignore_fields:
  • form
  • forms
    cache:
    enabled: true
    check:
    method: auto
    driver: auto
    prefix: g
    lifetime: 604800
    gzip: false
    redis:
    socket: false
    twig:
    cache: true
    debug: true
    auto_reload: true
    autoescape: false
    undefined_functions: true
    undefined_filters: true
    umask_fix: false
    assets:
    css_pipeline: false
    css_pipeline_include_externals: true
    css_pipeline_before_excludes: true
    css_minify: true
    css_minify_windows: false
    css_rewrite: true
    js_pipeline: true
    js_pipeline_include_externals: true
    js_pipeline_before_excludes: true
    js_minify: true
    enable_asset_timestamp: false
    collections:
    jquery: 'system://assets/jquery/jquery-2.x.min.js'
    errors:
    display: true
    log: true
    debugger:
    enabled: true
    shutdown:
    close_connection: true
    twig: true
    images:
    default_image_quality: 85
    cache_all: true
    cache_perms: '0755'
    debug: true
    auto_fix_orientation: false
    media:
    enable_media_timestamp: false
    upload_limit: 0
    unsupported_inline_types: { }
    allowed_fallback_types: { }
    session:
    enabled: true
    timeout: 1800
    name: grav-site
    secure: false
    httponly: true
    split: true
    path: null
    gpm:
    releases: stable
    proxy_url: null
    method: auto
    verify_peer: true

If you're using a custom theme, check you inject the Javascript properly using {{ assets.js() }} otherwise the debug bar js is not added to the page.

The debugger needs jQuery, doesn't it? I realized after excluding it in my project.

Yes that's another possible cause of the problem. It's usually added in most themes, but you need to make sure the theme loads it.