Firstly, in you trial, choose Corporate or anything above Corporate edition to try Database Engineering. If you still don't find it,
Goto View-> Workspaces & Commands, In the Commands tab, choose Complete. This should resolve, but in case it doesn't, right click on the package -> Code Engineering -> Generate DDL.
Please note, you might also have to set default database for tables prior to generating DDL (To set it at model level, so that all your tables are created in with that set, Settings -> Database Datatypes-> Select the product and check set as default)