Both PowerPoint and Google Slides both support live closed captions (subtitles) while you are presenting. Take a look at this YouTube video that demonstrates the automatic closed captions.
Follow these steps to set it up and test it in advance:
Alternatively, your web conferencing tool may offer closed captioning features or, if using Zoom, the meeting host may designate a participant to type the closed captions live during the Zoom event. If closed captioning is set up in a Zoom event, you can follow these instructions to view the subtitles.