Edits are saved on your copy of the meeting.
On Summary, edit the overview, a topic title, or the topic text. The timestamp on a topic stays as it is.
On Transcript, edit the words in a line. The speaker and the time stay as they are.
Choose the edit control on that block, change the text, and save. An empty edit is rejected. A summary overview or a transcript line can be up to 4,000 characters. A topic title can be up to 200 characters.
The same text is what a shared link shows after you save.