Как получить многие ко многим django?

class User(AbstractUser):
    patronymic = models.CharField(max_length=100, blank=True, null=True)
    department = models.ManyToManyField(Department)

class Department(models.Model):
    name = models.CharField(max_length=100)
    abbreviation = models.CharField(max_length=100, blank=False, null=False)
    description = models.TextField(max_length=500, blank=True, null=True)
    type_of_department = models.ForeignKey(TypeOfDepartment, default=None, on_delete=models.CASCADE)

from django.shortcuts import render

def index(request, username, department=None):
    print(request.user.department)
    return render(request, 'department/index.html', locals())