Local spins up an nginx process we called “Router” that listens on port 80. This serves as a proxy to the actual WordPress site that is listening on whatever port it is spun up on (usually something like port :10011)
This allows Local to have multiple WordPress sites running at the same time, as well as allow for the useful Site Domain (example.local) as opposed to a more generic port number like localhost:10011)
In your case, the actual WordPress site will be running Apache, but since it’s being proxied by the Router, that’s what the response header will show.