What if I've used my web service for signin and use Google as my primary web search engine? Most of my apps are either independent of - or dependent upon Google signin.

How do I transfer my Apps signin from Google to Apple if I want to do so? I've used Google browser and search engine for years, not often using Safari. That is just the way I evolved my computer use, not intended to avoid Apple's access through Safari. I also didn't like the Apple Mail format so I continue to use the Google Mail through Chrome, although I know there have been security issues with Chrome.