Adding an Option to the + Extension

PopClip Extensions
2

The source of that extension is here but it’s not easy to edit that.

Here’s a snippet instead that does what you want (the main difference is two \ns (newline characters) instead of one).

// #popclip
// name: Append
// icon: monospaced +
// language: javascript
pasteboard.text = pasteboard.text.trim() + "\n\n" + popclip.input.text.trim()

(The above block is an extension snippet — select it then click “Install Extension” in PopClip.)