Comment to Issues installing Nexus
If you have the proper setup key-secret pair (Studio->Settings->General) and your Studio->Dashboard->Server audit area shows all points as "OK" (green), you should see the Upgrade button directly in the Studio->Dashboard app.
I see that all checks on the server audit are ok but one thing I notice is that when looking at the una.io side it shows that I have no server and directs me to get tmd hosting which I already have. Would this have something to do with it?