On the Slide Show ribbon tab, select Subtitle Settings.
You can select the specific microphone you want to be used (if there is more than one microphone connected to your device), the position where the subtitles appear on the screen (bottom or top, and overlaid or separate from slide), and other display options. You can choose which language you want to speak while presenting, and which language the caption/subtitle text should be shown in (i.e. The feature isn't supported if you're using an earlier version of Windows.) Set up captions and subtitles ( Requires Windows 10, and PowerPoint for Microsoft 365 version 1.20178 or higher on Current Channel.
