PopClip won’t activate on a whitespace-only selection. However it will activate on an empty selection, by long pressing the mouse button (hold for 0.5 seconds). Alternatiely, Shift-click. Or use the PopClip keyboard shortcut to make it appear. Double-click will work in some text areas too.
In the extension config you’ll need to set requirements: [] to tell PopClip to show the extension’s actions when there is no selected text.
example
// #popclip - appear with "Paste" only (no selected text needed)
// name: paster
// requirements: []
// language: javascript
popclip.pasteText(`input text is '${popclip.input.text}'`)
