Basics things first, even if you are using a trial version but you still need to provide the license information and a developer key.
Instead of using a DDIC user, you can try using a BCUSER for your requirement as it is a part of the trial version.
You can try to include the SAP_ALL profile for your designated user.
SAP_ALL get’s generated automatically whenever you transport authorization objects.
You can generate SAP_ALL using report RSUSR406 or transaction SU21. This generates SAP_ALL only in the client where this report is executed. You can generate SAP_ALL using report AGR_REGENERATE_SAP_ALL. This report generates SAP_ALL in all clients.