The 'Fields Required' checks whether values for specified fields are set for a given transition.
You must select mandatory fields, when configuring the transition. For example:
JSU default behaviour is to apply the context settings – whether the field is actually configured for the issue in transition. This means that if a field that is required by this check, but has no valid context for the current issue, it will not be checked.
A workflow is configured so that the 'Ready for Review' transition has the 'Fields Required' check where the 'Reviewer' is mandatory. It will then copy the Reviewer to the Assignee, assigning the issue to the reviewer.
Supported Field Types