Now I use same config, as in original question:

s3 {
                key: "key"
                secret: "sec_key"
    
                credentials: [
                    {
                        host: "host:port"
                        bucket: "bucket_name"
                        key: "key"
                        secret: "sec_key"
                        multipart: false
                        secure: false
                    }
                ]
            } 

And pass output_url as:

dataset.upload(show_progress=True, verbose=True,
               output_url = "

:port/bucket_name/")

And get an error:

2024-05-28 16:31:40,818 - clearml.storage - INFO - Uploading: 0.00MB / 0.00MB @ 0.00MBs to /tmp/state.8qhb6dfu.json
2024-05-28 16:31:40,819 - clearml.storage - ERROR - Failed uploading: Connection was closed before we received a valid response from endpoint URL: "

:port/bucket/NAME/.datasets/NAME_/NAME__.4feaeb4d8285adbc778f61d262/artifacts/state/state.json".