You have 2 hours after typing your original response to go back in an edit!
Look for the 3 … in the lower right corner under your reply. Click there and it opens to a small menu. If you’re still within the time frame, at the bottom you’ll see an option for Edit.

You can also use the same 3 dots to click, Report Comment. That opens to a box where you can type to a moderator to correct a typo, delete a comment or make amendments. ☺️