In the "Execute Terminal Command (Async, non-blocking)" action, when typing quotes or apostrophes from the keyboard, they appear differently and obviously function differently because they don't work. I have to type the quotes/apostrophes into Safari, then copy & paste them into the textbox in BetterTouchTool.
Here's an example:
Quotes from BTT keyboard: “
Quotes from Safari keyboard: "
Apostrophe from BTT keyboard: ‘
Apostrophe from Safari keyboard: '
2018 MacBook Pro 13in
macOS Catalina 10.15.4 (Latest)
BetterTouchTool Version 3.372 (Latest)