First, open a new Google Doc. Then, click on the Tools menu at the top of the page and select Voice typing. A microphone icon will appear on the left side of your screen. If the language you want to use is not shown, you can click on the link above the microphone icon and choose the language you need.
Next, simply click on the microphone icon to activate the voice typing feature. Once the microphone turns red, you can start speaking, and your words will appear on the screen as you talk. This allows you to easily transcribe your audio file into text within the Google Doc.