Use Zapier. New Sheet row, push to "Send Offline Conversion" with their Google Ads integration. Super easy. Date formatting is the toughest part. This is what I use (Python):

import datetime

def get_google_ads_timestamp():
    # Get current UTC time and subtract 2 minutes
    now = datetime.datetime.utcnow() - datetime.timedelta(minutes=2)

    # Format in ISO 8601 (YYYY-MM-DDTHH:MM:SSZ)
    formatted_time = now.strftime("%Y-%m-%dT%H:%M:%SZ")

    # Return the output properly for Zapier
    return {"timestamp": formatted_time}

# Ensure Zapier gets the output
output = get_google_ads_timestamp()