Internal JavaScript Xmpp Server does not attach files for chat

Internal JavaScript Xmpp Server does not attach files for chat. Is it reduced functionality?

Afaik, Nextcloud doesn’t contain an internal JavaScript Xmpp Server. Do you eventually refer to the external JavaScript XMPP Chat app?
If yes, the following posting might be of interest for you: https://github.com/jsxc/jsxc/issues/302#issuecomment-199783430

Yes i mean JavaScript XMPP Chat.
But post https://github.com/jsxc/jsxc/issues/302#issuecomment-199783430 not resolve my problem.