Hi @brightside!
First of all take a look on this thread: Critical Problem Notification for GL-MT2500/GL-X3000/GL-XE3000
I think, this is because in GL GUI you didn't enable remote access. Try to enable it.
To get hostname and key you can use workaround. Generate ones on your PC and then use SCP to put it on router.
But maybe @bruce from support can help better.
Unfortunately, XE3000 don't support OP24 firmware, so it is hard to implement something custom without workarounds