Google Docs Voice Typing. If you're not sure if it will work in your language, you can check the google docs support page to find a full listing of available languages. With google docs, using the keyboard isn't your only option to add text.
If you're using the google docs app on a mobile device, then you can still use the google keyboard microphone to dictate text, but it doesn't.
The answer is that unfortunately voice typing in docs is only supported in chrome. You can also just talk and have google docs transcribe the words for you. It is possible to use voice for input on google docs, the feature is called 'voice typing', and can be found on the tools menu on a google doc or within google slides. Go to end of paragraph)