TestRail Lite is a Jira-native add-on that is installed directly on your Jira Cloud instance. It enables development and QA teams to create, manage, and report on tests directly within Jira.
The add-on can be installed via the Jira Marketplace. You need to go to Apps > Find new apps and search for TestRail Lite. Click on it and then Get app, then Try for Free. Jira will let you know when the app is available to use.
Before using TestRail Lite (as a Jira administrator) you will have to complete the Data Processing Agreement (DPA) to ensure the protection of your data under the GDPR legislation.
Note: Make sure to have a Full High Definition (1920×1080) resolution or above for an optimal interface experience.