1- You can bookmark a Test Case by selecting the checkbox to the left of a Test Case and click on Bookmark.
2- Alternatively, while the test case is open, you can click "More options" and choose "Add to bookmarks":
3opening it and clicking Add to Bookmark icon on the top right side
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2- Once the test case is bookmarked, you can click on your username on the top right corner of the screen where the bookmarked test case will be visible.will see it added under BOOKMARKS in the left panel.