How to manage channel's playlists using YouTube Data API?

I currently have a private Google (that includes YouTube) account with a YouTube channel. I want to create and generally manage playlists on channel account (instead of private account/channel). When I'm querying POST https://www.googleapis.com/youtube/v3/playlists I can only manage my private account.

I have tried this:

# Generated by Google Bard AIcurl -X GET \  -H "Authorization: Bearer [YOUR_API_KEY]" \  https://www.googleapis.com/youtube/v3/channels

I can see only my private account main channel.

And this:

# From: https://developers.google.com/youtube/v3/docs/channels/listcurl --request POST \'https://youtube.googleapis.com/youtube/v3/playlists?part=snippet,status&onBehalfOfContentOwnerChannel=[ChannelID]&key=[YOUR_API_KEY]' \  --header 'Authorization: Bearer [YOUR_ACCESS_TOKEN]' \  --header 'Accept: application/json' \  --header 'Content-Type: application/json' \  --data '{"snippet":{"title":"Test 1","description":"Test playlist."},"status":{"privacyStatus":"unlisted"}' \  --compressed

Returns:

{"error": {"code": 500,"message": "Internal error encountered.","errors": [      {"message": "Missing content owner id.","domain": "youtube.api.v3.RequestContextError","reason": "ERROR_CONTENT_OWNER_CHANNEL_WITHOUT_CONTENT_OWNER"      }    ],"status": "INTERNAL"  }}

When I apply my private account channel ID, it returns:

{"error": {"code": 403,"message": "The authenticated user cannot act on behalf of the specified Google account.","errors": [      {"message": "The authenticated user cannot act on behalf of the specified Google account.","domain": "youtube.common","reason": "accountDelegationForbidden"      }    ]  }}

As far as I understand, as long I'm not a YouTube Partner (which I'm not) I can't use it... Right?