This workflow demonstrates the use of the $item(index) method. This method is useful when you want to reference an item at a particular index. This example workflow makes POST HTTP requests to a dummy URL. Set node: This node is used to set the API key that will be used in the workflow later. This node returns a single item. This node can be replaced with other nodes, based on the use case. Customer Datastore node: This node returns the data of customers that will be sent in the body of the HTTP request. This node returns 5 items. This node can be replaced with other nodes, based on the use case. HTTP Request node: This node uses the information from both the Set node and the Customer Datastore node. Since, the node will run 5 times, once for each item of the Customer Datastore node, you need to reference the API Key 5 times. However, the Set node returns the API Key only once. Using the expression {{ $item(0).$node["Set"].json["apiKey"] }} you tell n8n to use the same API Key for all the 5 requests.
