I needed google drive for iphone6

You'll need a newer iPhone. Google Drive, is an app available in the App Store, but it requires an iPhone which can run iOS 14 or higher, which an iPhone 6 most definitely cannot run.

https://apps.apple.com/us/app/google-drive/id507874739

Google does not support their apps for anything that is still running older 32-bit versions of iOS or iPadOS. So all their current apps require either iOS 13 or newer, or 14 or newer. That is Google’s decision not to distribute older versions of their software products.

Start here. This is a Google reference. I have no idea about whether, and, if so how, it interfaces with any iPhone.

https://www.google.com/drive/