1. Open the PDF document in Highlights
Locate and tap the PDF file you want to open in the Highlights document browser:
The PDF opens in a document scene:
2. Select the text you want to strikethrough
If you use an Apple Pencil or mouse, this will bring up the full selection popover:
If you use your finger, this will bring up the standard selection popover (without color options).
3. Choose a color and tap the strikethrough button in the selection popover
Your annotation is added to the PDF and the text you added a strikethrough to appear in your notes which you can easily share.