Hi,
It looks like you are connected to HX Connect via Intersight. If so, you won't see the upgrade button.
You can upgrade your HyperFlex Edge cluster via Intersight.
Go to the HyperFlex cluster view. On the right click on the ... (Three dots) of the cluster and now you can easily upgrade the cluster.
Not only are you able to upgrade HXDP, but also ESXi with Intersight.
Kind Regards,
Joost.