When using Prefect deployment/agent, json file won't change

Help
, ,
1

I have a task (called in a flow) that modifies a json file. When running the flow locally in my terminal, the json file is successfully edited.
However, when running the code via a prefect deployment/agent, the json file is not edited despite the code logging success and no errors/exceptions were raised.

@task(name="Modify Json")
def modify_json()
        with open('json_path', 'r+') as f:
            dict= json.load(f)

            # updates json field
            dict['key'] = 'update'

            f.seek(0)
            json.dump(dict, f, indent=4)
            f.truncate()


        # log success
        logger.info(f"success")

@flow(name="test")
def test_json()
        modify_json()

if __name__ = "__main__":
        test_json()

I follow the deployment instructions here: