Your license key entitles you to a full installation of ePO 5.10.0, and populates the Software Catalog with the licensed Trellix products your company owns.
Without a license key, ePO runs in evaluation mode. Once the evaluation period expires, ePO ceases to function. You can add a license key at any time during or after the evaluation period.
Select Menu → Configuration → Server Settings, select License Key from the Setting Categories, then click Edit.
Type your License Key and click Save.