Sorry about this issue, @yuying .
We have udpated our script server with the fix. The script version is 336.
Please update your local script(Hookmark preferences window->Update->Check now).
After you update the script, please do the following:
(1)Install zotero-markdown-translator from GitHub - silentdot/zotero-markdown-translator: A simple Zotero translator that creates a Markdown Link when exporting
(2)In Zotero Settings->Export, make sure you have the following setting:
(3)Make sure the shortcut for Zotero Settings->Advanced->Shortcuts->Copy Selected items to clipboard is shift+command+C
Please let us know if you have any problem.
Thank you