To use Sales Simplify integration in n8n, start by adding the HTTP Request node to your workflow canvas and authenticate it using a generic authentication method. Once connected, you can make custom API calls to Sales Simplify to query the data you need using the URLs you provide, for example: after setting up the HTTP Request node, you can create a record in Sales Simplify by sending a POST request to the appropriate endpoint with your data payload. To update existing records, use a PATCH or PUT request with the record ID included in the URL, along with the updated information in the body. To retrieve data, simply use a GET request with the desired endpoint, ensuring you handle any necessary query parameters for filtering results.