'/youtubei/v1/' at "www.googleapis.com", gives out a 405 error page

for some reason this url: https://www.googleapis.com/youtubei/v1/ gives out this:

405. That’s an error.The request method GET is inappropriate for the URL /youtubei/v1/. That’s all we know.

and i tried:https://www.googleapis.com/youtubei/v1/search?key=[api_key_goes_here] and it won't work that way either andi wonder why this give out a 405 error page?the project im doing here is for innertube.