newbe question: how to test api form HTML form?

[Zhou Zola]

Dear whom read this message,
I curious on how windy API works, wish to track typhoon path, I did applied a Point Forecast API and follow the documentation to do query via post method by HTML form. But it failed everytime, API endpoint told me "Invalid request - "key", "model", "lat", "lon" or "parameters" are missing"

anyone can tell me the reason? is there any other sample code to test API ? PHP or SHELL are fine to me.Thank you in advance.

below are my code, I am not professional developer. for security reason I added underline in API key in my sample code, I will revoke this API if test passed

screenshot for your reference:

post failed: