Types are not recognized in methods

[aliqb]

If I have a integerField, the excel column will be number
but if I have a method in my model or serializer that return int, the excel column will be text
for ex:

class Statuses(models.IntegerChoices):
    SUPERVISOR = 0, _("awaiting supervisor's approval")
    EXPERT = 1, _("awaiting expert's approval")
    ACTIVE = 2, _("active")
    EXPIRE = 3, _("expired")
    EXTENDED = 4, _("extended")
    REJECT = -1, _("rejected")

    user = models.ForeignKey(User, on_delete=models.CASCADE)
    service = models.ForeignKey(Service, on_delete=models.CASCADE)
    status = models.IntegerField(choices=Statuses.choices, default=1)
    start_date = models.DateField(null=True, blank=True)
    duration = models.PositiveBigIntegerField(null=False)
    buy_date_time = models.DateTimeField(auto_now_add=True)
    paid_credit = models.PositiveIntegerField(null=True)

    @property
    def duration_hours(self):
        return self.duration // 3600000

    @property
    def total_price(self):
        return self.service.price * self.duration_hours

and a serializer with all fields, duration column will be number but total_price will be text
I seek in documentation but I didn't find a solution
use format for column data style does not work