I have read the FAQ and see that when a USB device is connected it should ask for permission and pop up in the server app. However this isn't the case for me.
I am using an LG G Stylo running Lineage OS 7.1.2, I installed the Virtualhere app from the playstore and can connect to it from my Windows 10 Desktop. The only problem is no devices plugged into the phone are showing up in the server.
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It might not actually have "usb host capability" even though the phone advertises it.
I used to have an old phone that did that too. I think its a hardware limitation in your older phone.
Unfortunately it looks like
Unfortunately it looks like this is the case. I tried it on an old Galaxy S5 and it worked right away.