Uploaded Debian packages don't show up in package registry

I followed the documentation on creating a Debian distribution. I have enabled both feature flags for Debian packages in my self-hosted gitlab CE instance.

I have created two distributions, "testing" and "unstable":

[
  {
    "id":1,
    "codename":"unstable",
    "suite":null,
    "origin":"Grep",
    "label":"grep.be",
    "version":"12",
    "description":"SReview packages for Debian unstable",
    "valid_time_duration_seconds":604800,
    "components":["main"],
    "architectures":["all","amd64","source"]
  },
  {
    "id":2,
    "codename":"testing",
    "suite":null,
    "origin":"Grep",
    "label":"grep.be",
    "version":"12",
    "description":"SReview packages for Debian testing",
    "valid_time_duration_seconds":604800,
    "components":["main"],
    "architectures":["all","amd64","source"]
  }
]

I then have the following in my .gitlab-ci.yml (edited to remove irrelevant jobs for this issue):

.deb: &deb
  stage: build
  image: $CI_JOB_NAME
  before_script:
  - apt-get update; apt-get -y --no-install-recommends install devscripts equivs git build-essential
  - mk-build-deps -r -i -t "apt-get -y -o Debug::pkgProblemResolver=yes --no-install-recommends"
  - DIST=${CI_JOB_NAME#*:}
  - VERSION=$(git describe|sed -e 's/^v//g')-0
  - DEBEMAIL="gitlab-runner auto build <nowhere@nowhere>" dch --distribution $DIST -v $VERSION --no-auto-nmu "gitlab automatic snapshot build for $DIST of $VERSION"
  script:
  - dpkg-buildpackage -us -uc -i -I.git
  after_script:
  - mkdir products
  - dcmd mv ../*ges products/
  - echo "GIT_DESCRIBE=$(git describe)" > dot.env
  artifacts:
    paths:
    - products
    reports:
      dotenv: dot.env
  tags:
  - docker

debian:testing:
  <<: *deb

debian:unstable:
  <<: *deb

.dput: &dput
  stage: release
  image: debian:stable
  allow_failure: true
  before_script:
  - apt-get update
  - apt-get -y install dput-ng
  - echo -e "[gitlab]\nmethod=https\nfqdn=https://gitlab-runner:$CI_JOB_TOKEN@$CI_SERVER_HOST\nincoming=/api/v4/projects/$CI_PROJECT_ID/packages/debian\n" > dput.cf
  script:
  - dput --config=dput.cf --unchecked --no-upload-log gitlab products/*.changes

dput:testing:
  <<: *dput
  dependencies:
  - debian:testing

dput:unstable:
  <<: *dput
  dependencies:
  - debian:unstable

Yet when the job runs, the packages do not show up in the Debian package repository.