ugettext_lazy not working in model validator

I'm using ugettext_lazy in a model validator to return the proper message to the frontend with the right language but it is not working.

from django.utils.translation import ugettext_lazy as _
class User(AbstractUser, BaseModel):
    mobile_number = models.CharField(
        'Mobile Number',
        validators=[
            RegexValidator(
                regex=r'^A Validator regex',
                message=_('Mobile Number is not Valid'),
                code='invalid_mobile',
            )
        ],
        max_length=32,
        blank=True,
    )

I am using Django Rest Framework and some of the errors are handled in the serizliers and the ugettext_lazy is working properly in the serializer errors but when it comes to the model messages, the translation is not working and it returns the English version of the error.