Is there an equivalent of flush_interval (Caddy) in HAProxy?

I’m having trouble with a piece of software

They have some issues working through proxies and they advise in their installation guide for Caddy to set flush_interval -1

By default, the proxy partially buffers the response for wire efficiency:

  • flush_interval is a duration value that adjusts how often Caddy should flush the response buffer to the client. By default, no periodic flushing is done. A negative value (typically -1) suggests “low-latency mode” which disables response buffering completely and flushes immediately after each write to the client, and does not cancel the request to the backend even if the client disconnects early. This option is ignored and responses are flushed immediately to the client if one of the following applies from the response:

Is there an equivalent option in HAProxy?

I guess that would be option http-no-delay