Debug FastAPI application in VSCode

i'm trying to debug an application (a web api) that use FastAPI (uvicorn) I'm also using poetry and set the projev virtual environment in vscode.

i read this tutorial to setup uvicorn and this one to setup vscode but i think i'm doing something wrong in set it up.

I tried to setup the launch.json both as python: module and python: current file

The problem seems that it doesn't recognize the project structure cause when i run the debug it stopped in an import statement with this error:

Exception has occurred: ImportError
attempted relative import with no known parent package

This is my current launch.json configuration:

"configurations": [
    {
        "name": "Python: local debug",
        "type": "python",
        "request": "launch",
        "program": "${workspaceFolder}/src/topic_service/service/__init__.py",
        "args" : ["--port", "8000"]
    },
]

I also tried to add a .env file setting PYTHONPATH:

PYTHONPATH=.:${PYTHONPATH}

Locally i run the application as follow:

poetry run uvicorn src.main:app --port 8080 --reload

Does anyone know how to correctly setup vscode to debug an uvicorn application?

Thank you

UPDATE: I also tried what this article says. the debugger seems to start but nothing happen (no breakpoint is triggered)