Trying to test my first FastApi code using uvicorn.

Following code written on Jupyter Notebook and saved as 'main.py' in the directory: /home/user

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
async def root():
    return {"message": "Hello World"}

From the same directory I am running:

$uvicorn main --reload

It is throwing the following error:

ERROR: Error loading ASGI app. Import string "main" must be in format ":".