To insert a gap into a read in the Chromatogram Editor select the nucleotide Sanger Reads Editor select a character or a gap in the corresponding location in the Chromatogram Area and press Space or , select Edit–>Insert gap context menu for switching the edit mode on.
While the selection is blinking, press space button.
After that the edit mode is switched off. For insert another gap press Space again.
You gap in the context item, or Actions->Edit->Insert gap in the main menu.
Thus, by holding the Space key, one can shift a Sanger read to the right.
You always can cancel the changes by pressing Ctrl+Z.