Allow requests without a Host Header

I am working on deprecating a legacy application in which I have no control over the client behavior. Specifically, the clients are making requests via HTTP/1.1, but do not include a Host header.

OpenLightSpeed follows the RFC in this case and returns a 404 error. I need to override this behavior and accept these requests. Is there any way to do so?

I was previously on a shared web hosting which used cPanel and LightSpeed Server, and it still accepts requests without Host header. I wish to achieve same with Cyberpanel and OpenLightSpeed. Can anyone point me in the right direction for this?