RESOLUTION
Promotional link for resellers is set up automatically as http://sitebuilder.domain.tld/Wizard?resellerId=<ID>After reseller is created please try to login under this reseller into Sitebuilder panel and go to Server -> Trial Sites Settings you should see something like this:
Promotional link : http://sitebuilder.domain.tld/Wizard?resellerId=3
Note: Place this link on your web site for your customers to access the SiteBuilder Wizard and try it out creating trial sites.
So to be able access reseller's wizard users should visit following link: http://sitebuilder.domain.tld/Wizard?resellerId=<ID>