To use Snapdocs 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 Snapdocs to query the data you need using the URLs you provide, for example: after setting up the HTTP Request node with authentication, you can automate various tasks like creating new closing orders or updating existing ones using POST and PUT methods respectively. For example, to create a new closing order, send a POST request to the Snapdocs API endpoint with the necessary order details in the request body. You can also retrieve data, such as lists of closing orders or their statuses, by sending GET requests to the appropriate Snapdocs API endpoints.