Unzipping files with Google Dataflow Bulk Decompress template?

I am trying to unzip uploaded zip files to Cloud Storage which contains only image files without any other folders inside.

I was able to do that with cloud functions but seems like I get memory-related issues when files get bigger. I found Dataflow templates (Bulk Decompress Cloud Storage Files) for this specific case and tried to run some jobs with similar to below parameters.

 {
        "jobName": "unique_job_name",
        "environment": {
            "bypassTempDirValidation": false,
            "numWorkers": 2,
            "tempLocation": "gs://bucket_name/temp",
            "ipConfiguration": "WORKER_IP_UNSPECIFIED",
            "additionalExperiments": []
        },
        "parameters": {
            "inputFilePattern": "gs://bucket_name/root_path/zip_to_extract.zip",
            "outputDirectory": "gs://bucket_name/root_path/",
            "outputFailureFile": "gs://bucket_name/root_path/failure.csv"
        }
}

As an output, I only get 1 file with the same name of my zip file without a file extension and with the type of text/plain.

Is this an expected behaviour? If someone could help me to unzip the file with Dataflow, I would be glad.

Thanks