The output script editor is for plain text edits only. If you'd like to further customize your output script, you can export it into a document or copy and paste it; then edit using Microsoft Word or other document editors.
Automatic Script: Can I add images to the script editor?
Learn that the Automatic Script editor supports plain text only and does not allow image uploads. To add images or further formatting, export your script and edit it in Microsoft Word or another document editor.