Zotero portable for which OS?
I found the Zotero 5 portable version, but it doesn't say what OS its for. I have systems with either Linux Mint or Windows 7 and had hoped to put the app and the data files all on a flash drive. Seems to be no place on GitHub to ask question.
If you're talking about https://github.com/pedrom34/ZoteroPortable/, it's not officially endorsed by Zotero, and it's for windows only.