Connect to another database and dumpdata from it in json format

My task is to populate my two existing City and Province model using two json files cities.json' and 'provinces.json.
Data in these files are as below.

provinces.json:

[
    {   "model": "salesnetwork.provinces",   
        "id": "1",
        "name": "EA"
    }
]

cities.json:

[
    {   "model": "salesnetwork.cities",
        "id": "1",
        "province_id": "1",
        "name": "Tabriz"
    }
]

Now I’m trying to poplulate my two models with these data. My models are as below.

class Provinces(models.Model):
    name = models.CharField(max_length=255, db_collation="utf8mb3_unicode_ci")

    class Meta:
        db_table = "provinces"


class Cities(models.Model):
    province = models.ForeignKey("Provinces", models.DO_NOTHING)
    name = models.CharField(max_length=255, db_collation="utf8mb3_unicode_ci")

    class Meta:
        db_table = "cities"

(My bad for naming my model Cities instead of City and Provinces instead of ‘Province’; I’ve created these models via inspectdb command and since I didn’t know if changing these model names could cause problems or not, I decided to leave the names as they were).
When I try using command py .manage.py loaddata provinces.json I get the following error:

Traceback (most recent call last):
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.com.venvlibsite-packagesdjangocoreserializersjson.py", line 69, in Deserializer
    objects = json.loads(stream_or_string)
  File "C:UsersVahid MoradiAppDataLocalProgramsPythonPython310libjson__init__.py", line 335, in loads
    raise JSONDecodeError("Unexpected UTF-8 BOM (decode using utf-8-sig)",
json.decoder.JSONDecodeError: Unexpected UTF-8 BOM (decode using utf-8-sig): line 1 column 1 (char 0)

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.commanage.py", line 22, in <module>
    main()
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.commanage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.com.venvlibsite-packagesdjangocoremanagement__init__.py", line 446, in execute_from_command_line
    utility.execute()
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.com.venvlibsite-packagesdjangocoremanagement__init__.py", line 440, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.com.venvlibsite-packagesdjangocoremanagementbase.py", line 402, in run_from_argv
    self.execute(*args, **cmd_options)
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.com.venvlibsite-packagesdjangocoremanagementbase.py", line 448, in execute
    output = self.handle(*args, **options)
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.com.venvlibsite-packagesdjangocoremanagementcommandsloaddata.py", line 102, in handle
    self.loaddata(fixture_labels)
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.com.venvlibsite-packagesdjangocoremanagementcommandsloaddata.py", line 163, in loaddata
    self.load_label(fixture_label)
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.com.venvlibsite-packagesdjangocoremanagementcommandsloaddata.py", line 251, in load_label
    for obj in objects:
  File "D:ProjectsNavid MotorWebsiteDjangoNavidMotor.com.venvlibsite-packagesdjangocoreserializersjson.py", line 74, in Deserializer
    raise DeserializationError() from exc
django.core.serializers.base.DeserializationError: Problem installing fixture 'D:ProjectsNavid MotorWebsiteDjangoNavidMotor.comprovinces.json'::

and by the looks of it, this time the problem is json.decoder.JSONDecodeError: Unexpected UTF-8 BOM (decode using utf-8-sig): line 1 column 1 (char 0), which I have no idea how to resolve and didn’t find any instruction on how to solve this issue.
I did study the following questions, but all were for problems relating json library inside .py files, and since my problem occurs in command line using manage.py commands, I couldn’t apply those solutions for my problem.
Possible simillar questions, but could not use the answers given:

1. First
2. Second
3. Third