To view requirements linked to a test case version, navigate to the desired version of the test case. On the left side vertical menu, click on the icon. It will expand to show the list of linked requirements, if any. Note that linking of requirements to a test case version can be done in the project's Requirements tab under the desired requirement.
Users will need view permissions for test coverage to view linked requirements. Depending on the settings of a user's project permissions, they may be able to view all test cases or just a subset of them.