The googleapis website is blocked from being used from Roblox’s HTTPService directly. That is why you are getting the “403 Forbidden” error. Although it is still completely possible to access googleapis.com or any other “forbidden” sites using a proxy.
This thread explains how to set-up a proxy to work with HTTPService on roblox, although it could be hard to wrap your head around it at first, but using a proxy is the only possible way of accessing the api for what you are trying to accomplish.
Hope this answers your question 