llm, 
    requests=Requests(), 
    verbose=True,
    return_intermediate_steps=True # Return request and response text
)
output = chain("whats the most expensive shirt?")
> Entering new OpenAPIEndpointChain chain...
> Entering new APIRequesterChain chain...
Prompt after formatting:
You are a helpful AI Assistant. Please provide JSON arguments to agentFunc() based on the user's instructions.
API_SCHEMA: ```typescript
/* API for fetching Klarna product information */
type productsUsingGET = (_: {
/* A precise query that matches one very small category or product that needs to be searched for to find the products the user is looking for. If the user explicitly stated what they want, use that as a query. The query is as specific as possible to the product name or category mentioned by the user in its singular form, and don't contain any clarifiers like latest, newest, cheapest, budget, premium, expensive or similar. The query is always taken from the latest topic, if there is a new topic a new query is started. */
		q: string,
/* number of products returned */
		size?: number,
/* (Optional) Minimum price in local currency for the product searched for. Either explicitly stated by the user or implicitly inferred from a combination of the user's request and the kind of product searched for. */
		min_price?: number,
/* (Optional) Maximum price in local currency for the product searched for. Either explicitly stated by the user or implicitly inferred from a combination of the user's request and the kind of product searched for. */
		max_price?: number,
}) => any;
```
USER_INSTRUCTIONS: "whats the most expensive shirt?"
Your arguments must be plain json provided in a markdown block:
ARGS: ```json
{valid json conforming to API_SCHEMA}
```
rtdocs_stable/api.python.langchain.com/en/stable/modules/chains/examples/openapi.html