Descript automatically aligns your transcript with the audio in the timeline but you may want to make an adjustment to the timing in the Wordbar to assure your transcript, Fancy Captions or exported subtitles are lined up correctly.
To do so, move your mouse over a word boundary and press either Command (MacOS) or Control (Windows) to display the trim tool and adjust the boundary right or left to your desired location.
Word-level adjustment
Word boundary adjustment must be performed on a per-word basis. You may need to zoom in a little on the timeline to get the trim tool to appear in tightly spaced words.