Action failed to run on my repo

[csj]

I tried following the steps and ran the workflow manually on my repo to generate the table the first time (without waiting for the timer to fire). The AOC_SESSION secret is correctly added in my repo.

The Run k2bd/advent-readme-stars@v1 step failed, here is its output:

Run k2bd/advent-readme-stars@v1
  with:
    userId: 174098
    sessionCookie: ***
    tableMarker: <!--- advent_readme_stars table --->
    starSymbol: ⭐
    headerPrefix: ##
    readmeLocation: README.md
/usr/bin/docker run --name a68251537f80c168747cd92339d70696f9b51_3a71a7 --label 6a6825 --workdir /github/workspace --rm -e INPUT_USERID -e INPUT_SESSIONCOOKIE -e INPUT_LEADERBOARDID -e INPUT_TABLEMARKER -e INPUT_STARSYMBOL -e INPUT_YEAR -e INPUT_HEADERPREFIX -e INPUT_READMELOCATION -e HOME -e GITHUB_JOB -e GITHUB_REF -e GITHUB_SHA -e GITHUB_REPOSITORY -e GITHUB_REPOSITORY_OWNER -e GITHUB_RUN_ID -e GITHUB_RUN_NUMBER -e GITHUB_RETENTION_DAYS -e GITHUB_RUN_ATTEMPT -e GITHUB_ACTOR -e GITHUB_WORKFLOW -e GITHUB_HEAD_REF -e GITHUB_BASE_REF -e GITHUB_EVENT_NAME -e GITHUB_SERVER_URL -e GITHUB_API_URL -e GITHUB_GRAPHQL_URL -e GITHUB_REF_NAME -e GITHUB_REF_PROTECTED -e GITHUB_REF_TYPE -e GITHUB_WORKSPACE -e GITHUB_ACTION -e GITHUB_EVENT_PATH -e GITHUB_ACTION_REPOSITORY -e GITHUB_ACTION_REF -e GITHUB_PATH -e GITHUB_ENV -e RUNNER_OS -e RUNNER_ARCH -e RUNNER_NAME -e RUNNER_TOOL_CACHE -e RUNNER_TEMP -e RUNNER_WORKSPACE -e ACTIONS_RUNTIME_URL -e ACTIONS_RUNTIME_TOKEN -e ACTIONS_CACHE_URL -e GITHUB_ACTIONS=true -e CI=true -v "/var/run/docker.sock":"/var/run/docker.sock" -v "/home/runner/work/_temp/_github_home":"/github/home" -v "/home/runner/work/_temp/_github_workflow":"/github/workflow" -v "/home/runner/work/_temp/_runner_file_commands":"/github/file_commands" -v "/home/runner/work/advent-of-code-2021/advent-of-code-2021":"/github/workspace" 6a6825:1537f80c168747cd92339d70696f9b51
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/local/lib/python3.9/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/usr/local/lib/python3.9/site-packages/advent_readme_stars/__main__.py", line 8, in <module>
    edited = update_readme(lines)
  File "/usr/local/lib/python3.9/site-packages/advent_readme_stars/update.py", line 70, in update_readme
    new_readme = insert_table(reduced)
  File "/usr/local/lib/python3.9/site-packages/advent_readme_stars/update.py", line 53, in insert_table
    stars_info = sorted(list(get_progress()), key=lambda p: p.day)
  File "/usr/local/lib/python3.9/site-packages/advent_readme_stars/progress.py", line 20, in get_progress
    leaderboard_info = res.json()
  File "/usr/local/lib/python3.9/site-packages/requests/models.py", line 910, in json
    return complexjson.loads(self.text, **kwargs)
  File "/usr/local/lib/python3.9/json/__init__.py", line 346, in loads
    return _default_decoder.decode(s)
  File "/usr/local/lib/python3.9/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/local/lib/python3.9/json/decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

[csj]

Ahh .. I hadn't actually created a private leaderboard. I created it, tried it again, and it worked fine. I'll amend your instructions to include this step.