What you have is a network attached storage device. That device will determine whether it supports SMB1 or (the newer) SMB2, You are correct in that you need to go to the manufacturers website for the external device to see if it will support SMB2. It may be a firmware update is required or, depending on the age it may only support SMB1.
If it is SMB1 only then you have no option but to enable windows support for SMB1, or you cannot use it to connect to windows.
If it has the option to enable SMB2 (either after an update, or currently) will depend on the settings of the device and not windows.
If you can post the make and model of the external drive then I may be able to find it and help you with the detail. Approximately how old is the external drive?