You must have got an email after downloading the Enterprise Edition that consisting the procedure to Activate the trial license (please do check your SPAM folder as well )
Also the procedure is given below as well
Trial Activation for LepideAuditor for Active Directory
1. Run the setup file and install the software.
2. Please click Domain Management and add the Domain Controller
3. Please click the License Information tab.
4. Now, click on “Get Quote”.
5. In the popup, please select “Generate License Request File”
6. Send the Info file(saved on your Desktop) to sales@lepide.com and activation key will be sent to you as per the details filled by you.