NerdMiner 4.1 links to this extension on its own: nothing to paste. Only an older NerdMiner asks for its token, printed once at startup and kept in ~/Library/Application Support/NerdMiner/companion-token (cat ~/Library/Application\ Support/NerdMiner/companion-token); pasting the whole line is fine.
Change only if you started NerdMiner with --stats-port. It prints "Companion stats: http://127.0.0.1:<port>/stats" at startup; that port goes here.
The forum. Sign in there once; the extension reuses that session for chat and presence.