Get a Foreign Key value with django-rest-framework serializers – Postgresql

I’m using the django rest framework to create an API.

models.py

class DepartmentModel(models.Model):
    DeptID = models.AutoField(primary_key=True)
    DeptName = models.CharField(max_length=100)

    def __str__(self):
        return self.DeptName

    class Meta:
        verbose_name = 'Department Table'

class EmployeeModel(models.Model):
    Level_Types = (
        ('Genin', 'Genin'),
        ('Chunin', 'Chunin'),
        ('Jonin', 'Jonin'),
    )

    EmpID = models.AutoField(primary_key=True)
    EmpName = models.CharField(max_length=100)
    Email = models.CharField(max_length=100,null=True)
    EmpLevel = models.CharField(max_length=20, default="Genin", choices=Level_Types)
    EmpPosition = models.ForeignKey(DepartmentModel, null=True, on_delete=models.SET_NULL)

    class Meta:
        verbose_name = 'EmployeeTable'  # Easy readable tablename - verbose_name

    def __str__(self):
        return self.EmpName

serializer.py

from appemployee.models import EmployeeModel,DepartmentModel
        
class EmployeeSerializer(serializers.ModelSerializer):

    emp_dept = serializers.CharField(source='DepartmentModel.DeptName')
    class Meta:
        model = EmployeeModel
        fields = ('EmpID','EmpName','Email','EmpLevel','emp_dept')

views.py

class EmployeeTable(APIView):

    def get(self,request):
        try:
            emp_obj = EmployeeModel.objects.all()
            empserializer = EmployeeSerializer(emp_obj,many=True)
        except Exception as err:
            return Response(err)
        return Response(empserializer.data)

this would provide me with:

[
    {
        "EmpID": 1,
        "EmpName": "Hashirama Senju",
        "Email": "[email protected]",
        "EmpLevel": "Jonin",
        "EmpPosition": 1
    },
    {
        "EmpID": 2,
        "EmpName": "Tobirama Senju",
        "Email": "[email protected]",
        "EmpLevel": "Jonin",
        "EmpPosition": 2
    },
    {
        "EmpID": 3,
        "EmpName": "Hiruzen Sarutobi",
        "Email": "[email protected]",
        "EmpLevel": "Jonin",
        "EmpPosition": 5
    }
]

what i really want is

[
    {
        "EmpID": 1,
        "EmpName": "Hashirama Senju",
        "Email": "[email protected]",
        "EmpLevel": "Jonin",
        "DeptName": "Hokage"
    },
    {
        "EmpID": 2,
        "EmpName": "Tobirama Senju",
        "Email": "[email protected]",
        "EmpLevel": "Jonin",
        "DeptName": "Hokage"
    },
    {
        "EmpID": 3,
        "EmpName": "Hiruzen Sarutobi",
        "Email": "[email protected]",
        "EmpLevel": "Jonin",
        "DeptName": "Hokage"
    }
]

DeptName is in the department model . I want to combaine the results of both serializers and display it.

PS: The JSON result is just for an example. Cannot display real data.