How should I set the url prefix for the onlyoffice server ？

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hey @Hason

Virtual paths for the Document Server can be set only using proxy.
Nginx installed with the Document Server on the same server to be configured as proxy.

  1. Install Document Server on a custom port using the official installation guide.

  2. Run Nginx as proxy on ports 80/443 using this article https://github.com/ONLYOFFICE/document-server-proxy/tree/master/nginx#readme

  3. Use the following configuration file for Nginx https://github.com/ONLYOFFICE/document-server-proxy/blob/master/nginx/proxy-to-virtual-path.conf

Link to general information: Using ONLYOFFICE Docs behind the proxy - ONLYOFFICE