I haven’t used the app, but I believe it removes the requirement to connect to a monitor. If you connect to a monitor then you don’t need the app, as the MacBook will stay awake (as per Energy preferences) when closed.
(I’m using an older MBP as a sever and just leave the lid open)
if it is near a monitor, why not plug that in? That would prevent it from going to deep sleep, and allow network access to wake it. You should also be able to use an HDMI dummy plug to get the same effect?