how to fix ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/uvicorn/protocols/http/h11_impl.py", line 428, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/uvicorn/middleware/proxy_headers.py", line 78, in __call__
    return await self.app(scope, receive, send)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/fastapi/applications.py", line 276, in __call__
    await super().__call__(scope, receive, send)
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/starlette/applications.py", line 122, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/starlette/middleware/errors.py", line 184, in __call__
    raise exc
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/starlette/middleware/errors.py", line 162, in __call__
    await self.app(scope, receive, _send)
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/starlette/middleware/cors.py", line 83, in __call__
    await self.app(scope, receive, send)
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/starlette/middleware/exceptions.py", line 79, in __call__
    raise exc
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/starlette/middleware/exceptions.py", line 68, in __call__
    await self.app(scope, receive, sender)
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/fastapi/middleware/asyncexitstack.py", line 21, in __call__
    raise e
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
    await self.app(scope, receive, send)
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/starlette/routing.py", line 718, in __call__
    await route.handle(scope, receive, send)
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/starlette/routing.py", line 276, in handle
    await self.app(scope, receive, send)
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/starlette/routing.py", line 66, in app
    response = await func(request)
               ^^^^^^^^^^^^^^^^^^^
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/fastapi/applications.py", line 231, in openapi
    return JSONResponse(self.openapi())
                        ^^^^^^^^^^^^^^
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/fastapi/applications.py", line 206, in openapi
    self.openapi_schema = get_openapi(
                          ^^^^^^^^^^^^
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/fastapi/openapi/utils.py", line 423, in get_openapi
    definitions = get_model_definitions(
                  ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/boika/PycharmProjects/helpsol_core_backend/venv/lib/python3.11/site-packages/fastapi/utils.py", line 44, in get_model_definitions
    m_schema, m_definitions, m_nested_models = model_process_schema(
                                               ^^^^^^^^^^^^^^^^^^^^^
  File "pydantic/schema.py", line 582, in pydantic.schema.model_process_schema
  File "pydantic/schema.py", line 623, in pydantic.schema.model_type_schema
  File "pydantic/schema.py", line 256, in pydantic.schema.field_schema
  File "pydantic/schema.py", line 463, in pydantic.schema.field_type_schema
  File "pydantic/schema.py", line 853, in pydantic.schema.field_singleton_schema
  File "pydantic/schema.py", line 702, in pydantic.schema.field_singleton_sub_fields_schema
  File "pydantic/schema.py", line 528, in pydantic.schema.field_type_schema
  File "pydantic/schema.py", line 927, in pydantic.schema.field_singleton_schema
  File "<frozen abc>", line 123, in __subclasscheck__
TypeError: issubclass() arg 1 must be a class