Sometimes you may have "closed" a lesson for grading (by committing all student work) but you wish to grant an extension to a particular student to allow them to continue working within the lesson. In this case, you can "grant an extension" to unlock the lesson for that student. Granting an extension will clear all grading and feedback that may have been already entered for that student. The student must complete and recommit their work in order to be regraded.
You can grant an extension by navigating to Course Progress > Students > Search for the lesson, then search for the student, select the tick icon, and select Grant Extension.
If all students require extensions, navigate through the Schedule tab, then select the three vertical dots and uncommit the lesson.
You can then reset a new automatic due date for the future, or manually commit all lessons using the Commit Lesson or Commit Sections button at the time you determine.