Servicing a Vuelta XRP Disc Hub
I don't have specific experience with this one, but the pictures suggest it works one of two ways:


From where you're at now, you bonk the end of the axle on the non-drive sufficiently hard and the axle slides out, possibly taking the freehub with it, or if not then letting it be removed.
You put the 5mm allen in the drive side end and a cone wrench on the bit with the cone wrench flats next to it, figure out if it's a left or right thread, break that connection and unscrew it, and the hub comes apart that way. I think this is more probable.