RE: Connect your Bot to the World - XML, JSON, Web Services, HTML Scraping, Twitter, Facebook, Telegram, Email

For some example scripts that call web services see,

https://www.botlibre.com/script?instance-filter=public&name-filter=&category-filter=Self&tag-filter=web+service&language-filter=&display=grid&instance-restrict=None&start-filter=&end-filter=&page-size=56&instance-sort=MonthlyConnects&content-rating=Mature&search=Search

I would also recommend you test your API using curl or postman first to ensure you are calling it correctly.
Also check the chat debug log for the error.