Filter on category in django

I was doing the project on Django & react using RestAPI to get into it more deeply. I have a problem with the view part. There are models; Course, CourseCategory.

CourseCategory is about what category a course is related to (which is ForeignKey).

I have list all the courses in one page where a certain category is clicked. But I don't know how to do it in the right way.

Here is my model

   class CourseCategory(models.Model):
    title = models.CharField(max_length=150)
    description = models.TextField()
    
    def __str__(self):
        return self.title 



class Course(models.Model):
    category = models.ForeignKey(CourseCategory, on_delete=models.CASCADE, null=True)
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, null=True)
    name = models.CharField(max_length=100, null=False , blank= False)
    brief = models.TextField(null=False , blank= False)
    image = models.ImageField(upload_to='img/%y/m/%d', default='img/1.png')
    
    def __str__(self):       
        return self.name 

and here is my view where i tried to write a filter function

class CourseList(generics.ListCreateAPIView):
    queryset = Course.objects.all()
    serializer_class = CourseSerializer
    #permission_classes = [IsAuthenticated]
    #authentication_classes = [TokenAuthentication]
    

  

    def get_queryset2(self):
        qs = super().get_queryset()
        if 'result' in self.request.GET:
            cat = int(self.request.GET['result'])
            qs = Course.objects.filter( category=cat )
        return qs

when tried to test that by writing the id of the category it's doesn't work like this enter image description here enter image description here

so is there anyone who can help, please

def get_queryset2(self):
    qs = super().get_queryset()
    if 'result' in self.request.GET:
        cat = int(self.request.GET['result'])
        cat_ins = CourseCategory.objects.filter(title=cat)
        qs = Course.objects.filter(category=cat_ins)
    return qs