Now i can do that by spawning subprocess like this:

app = FastAPI()

@app.post("/create_task")
def create_task(input_data: InputData):
    os.system("python main-pipeline.py")
   
    return {
        "message": "Task created successfully",

    } 

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8000)