Issues while using related names

This is the Course and LearnerCourse model:

class Course(BaseModel, Timestamps, SoftDelete):    name = models.TextField(_("Course Name"), max_length=100,                            blank=True, null=True, unique=False)    description = models.TextField(        _("Course Description"), blank=True, null=True)    course_number = models.CharField(        max_length=15, null=True, blank=True, unique=True)....class LearnerCourse(BaseModel, Timestamps, SoftDelete):    course = models.ForeignKey(Course, verbose_name=_("Course"), on_delete=models.CASCADE, db_index=True, related_name='course_learner_courses')    learner = models.ForeignKey(Learner, verbose_name=_("Learner Course"), on_delete=models.CASCADE, db_index=True)    course_subscription = models.ForeignKey(CourseSubscription, null=True, on_delete=models.CASCADE, db_index=True)    enroll_date = models.DateTimeField(verbose_name=_("Course Enroll Date"))    is_favourite = models.BooleanField(default=False)

in LearnerCourse used the related name for the course field, after thatWhen used like this

    details = LearnerCourse.objects.filter(learner=learner_id).all().order_by('-datetime_created')        print("details", details)       courses = details.course_learner_courses.all()      print("courses", courses)   

which causes an error 'SafeDeleteQueryset' object has no attribute 'course_learner_courses'Please give me some suggestions to fix this problem.