an extension of issue #1608
there are other locations where client.files_upload_v2 references the argument channel_id instead of channel which causes the following error:
TypeError: slack_sdk.web.client.WebClient.files_completeUploadExternal() got multiple values for keyword argument 'channel_id'

The page URLs
https://tools.slack.dev/python-slack-sdk/tutorial/uploading-files/