I have a BTB Smart Hub 1 which is fairly similar. The settings you want are under 'Advanced Settings...My Network...IPv4 configuration. Click on the Hub gateway IP address shown and change the '1' to a '0'.
Then you can change the 'Server address range' by selecting 'Custom'...'Set' and changing the '1's to '0's.
Then 'Save'
BTW, the image you posted won't be public until a mod approves it. You can see it but I only see a yellow triangle.