Django Taggit adding a list of tags to tag field by post save method

i am using Django Taggit 3.0.0 with python 3.10.5 and django 4.0.6 adding a list of tags to tag field by post save method i tried below codes which works well no error at all but the tags list is not assigned to the resource ragfield but it is getting listed in admin pannel tags model table.

and i also want to add initial tags to each tagfield Model

class resource(models.Model):
    title=models.CharField(max_length=100)
    size=models.CharField( max_length=20, default="")
    desc=models.TextField(default="")
    file=models.FileField(default="", blank=True)
    url= models.URLField(max_length=200, blank=True)
    Brand = models.ForeignKey(brand,on_delete=models.CASCADE, default="")
    Model = models.ForeignKey(model,on_delete=models.CASCADE, default="")
    Categories = models.ForeignKey(category,on_delete=models.CASCADE, default="")
    update_at=models.DateField(auto_now=True)
    slug=models.SlugField(default="")
    Tags = TaggableManager()


def tag_set(sender, instance,*arg, **kwargs):
    ans= array_tag(instance)
    # print(ans)
    mylist = ["firmware", "download", "gsm"]
    instance.title='check'
    instance.Tags.add(*ans)
  
post_save.connect(tag_set, sender=resource)  
def array_tag(instance):
    return [instance.title ,instance.desc,instance.size, instance.Brand.title ,instance.Model.title ,instance.Categories.title]