How can I resolve the 'Invalid URL' error when fetching token prices from the CoinMarketCap API in n8n?

I'm new to n8n and am setting up an AI agent to look up token prices using the CoinMarketCap API. However, I keep receiving an error that says "invalid url".

Here's what I've tried so far:

1. I used custom authentication with JSON as follows:

JSONCopied
{  
  "headers": {  
    "X-CMC_PRO_API_KEY": "KEY"  
  }
}

2. I also attempted header authentication using name (header) and value (api_key).

Workflow details:

• Node type: @n8n/n8n-nodes-langchain.toolHttpRequest
• Node version: 1.1 (Latest)
• n8n version: 1.76.1 (Cloud)
• Time: 29/01/2025, 21:25:19

Error stack trace:

``
NodeApiError: Invalid URL at RoutingNode.runNode (/usr/local/lib/node_modules/n8n/node_modules/n8n-core/dist/execution-engine/routing-node.js:159:23)
at WorkflowExecute.runNode (/usr/local/lib/node_modules/n8n/node_modules/n8n-core/dist/execution-engine/workflow-execute.js:683:23)
at /usr/local/lib/node_modules/n8n/node_modules/n8n-core/dist/execution-engine/workflow-execute.js:890:51
at /usr/local/lib/node_modules/n8n/node_modules/n8n-core/dist/execution-engine/workflow-execute.js:1224:20

I'm looking for guidance on how to correct the URL or adjust the workflow to eliminate this error.