I get an access violation. I am using a c++ dll with a single function that tries to extract a string from a PyObject. It seems the PyObject *args argument is not right type. This is from similar examples posted elsewhere. Passing a c_char_p (to a function taking a c_char_p) and returning a PyObject * works fine.

Load a C++ dll and call a function with an object. Set correct path.

Using msvc 2022 and Python 3.9.

Python:

import ctypes
import sys
import os 

y = __file__
str_path = os.path.dirname(os.path.realpath("..\\..\\string\\x64\\Debug\\string.dll"))
handle = ctypes.CDLL(str_path + "/string.dll")     

handle.My_Function3.argtypes = [ctypes.py_object]
handle.My_Function3.restype = ctypes.py_object

z = handle.My_Function3(ctypes.py_object(y))

print(z)

Create C++ string.dll adding a single function.
C++ file added to string.dll (added to Windows dll) dllmain.cop is unchanged:

function.cpp:

#include "pch.h"
#define PY_SSIZE_T_CLEAN
#include <Python.h>

char s[100];

static PyObject *MyError;

extern "C"
{
    __declspec(dllexport) PyObject* __stdcall My_Function3(PyObject *args)
    {
        const char* str;
        char s[100];

                // Code fails here with access violation
        if (!PyArg_ParseTuple(args, "s", &str))
            return NULL;
 
        if (strlen(str) > 100)
        {
            PyErr_SetString(MyError, "Error: string too long");
            return NULL;
        }

        strcat_s(s, 100, str);
        return Py_BuildValue("s", s);
    }
}