How to get a parent message of a slack thread in Zapier

Hey, I want to get the parent message in a slack thread using a thread id.  I have never worked with API's but today I gave it a try.  I got this code from chat gpt

import os
from slack_sdk import WebClient
from slack_sdk.errors import SlackApiError

def main(input_data):
    # Retrieve the Slack API token from the environment variables
    SLACK_API_TOKEN = os.environ["SLACK_API_TOKEN"]

    # Initialize the WebClient with the API token
    client = WebClient(token=SLACK_API_TOKEN)

    try:
        # Call the conversations.history method using the WebClient
        # The client passes the token you included in initialization    
        result = client.conversations_history(
            channel=input_data["Thread_ID"],
            inclusive=True,
            oldest="1610144875.000600",
            limit=1
        )

        # Get the first message in the result
        message = result["messages"][0]

        # Print the message text to the console
        print(message["text"])

    except SlackApiError as e:
        print(f"Error: {e}")

I used this python code found there but I got Traceback error, I also didn't know how to get the slack api token so didn’t add them there, could anyone tell me how to do them and what am doing wrong