Xray actually supports timebomb licenses, however the following steps need to be performed:
Step-by-step guide
- Head on to the darkfeatures menu of Jira. http://host_server/secure/SiteDarkFeatures!default.jspa
- Add this feature com.xpandit.raven.license.impl.AtlassianLicenseManager.tm.test
- Copy a timebomb license from https://developer.atlassian.com/platform/marketplace/timebomb-licenses-for-testing-server-apps/
- Add it to Manage Apps Xray License
- The license is now a trial ending at the end of the license
Link for related documentation
Timebomb licenses for testing server apps
Licensing your Jira applications