I'm running QGIS 3.4 server on Windows 10. The docs here say that you need to add these lines to httpd.conf to enable QGIS server logging:
FcgidInitialEnv QGIS_SERVER_LOG_FILE /var/log/qgis/qgisserver.log
FcgidInitialEnv QGIS_SERVER_LOG_LEVEL 0
(Those lines are also referenced in several other: here and here for example)
But those only work if mod_fcgid is installed. Apparently you have to jump through some moving-target hoops to install mod_fcgid on Windows.
Is there a way to enable QGIS server logging without mod_fcgid?