def METHOD_NAME(sendgrid_erasure_identity_email: str, sendgrid_secrets):
    """
    Confirm whether contact exists by calling contact search by email api and comparing resulting firstname str.
    Returns contact ID if it exists, returns None if it does not.
    """
    base_url = f"https://{sendgrid_secrets['domain']}"
    body = {"emails": [sendgrid_erasure_identity_email]}
    headers = {
        "Authorization": f"Bearer {sendgrid_secrets['api_key']}",
    }
    contact_response = requests.post(
        url=f"{base_url}/v3/marketing/contacts/search/emails",
        headers=headers,
        json=body,
    )
    # we expect 404 if contact doesn't exist
    if 404 == contact_response.status_code:
        return None
    return contact_response.json()["result"][sendgrid_erasure_identity_email]["contact"]