Django error：不能分配必须是实例

当我试图在我的一个表中运行INSERT时，我得到以下错误.

无法分配"1":"Team.department_id"必须是"department"实例

诚然，我有点不确定我是否正确使用了外键概念.我试图运行的插入和我的模型中的一个片段.py如下所示.

我想做的是，当有人想要创建一个新团队时.他们必须把它附在一个部门.因此，部门ID应该在两组表中.

new_team = Team(
    nickname = team_name,
    employee_id = employee_id,
    department_id = int(Department.objects.get(password = password, department_name = department_name).department_id)
)

models.py

class Department(models.Model):  
    department_id = models.AutoField(auto_created=True, primary_key=True, default=1)  
    department_name = models.CharField(max_length=60)
    head_id = models.CharField(max_length=30)
    password = models.CharField(max_length=128)


class Team(models.Model):  
    team_id = models.AutoField(primary_key=True)
    department_id = models.ForeignKey('Department', related_name = 'Department_id')
    employee_id = models.CharField(max_length=30)
    nickname = models.CharField(max_length=60)
    team_image = models.ImageField(upload_to=get_image_path, blank=True, null=True)