I have two Python routes which allow my frontend on React to authorize with Github Oauth. It happens like that:

• Frontend user goes to BACKEND_URL/api/v1/oauth/github from page FRONTEND_URL/login
• Backend returns redirect to ;redirect_uri=FRONTEND_URL/login?app=github&scope=user:email
• Frontend redirects to Github and gets code in FRONTEND_URL/login?app=github&code=CODE
• Then useEffect fetches BACKEND_URL/api/v1/oauth/github/access?code=CODE and gets access token

I am new to Oauth, do I have correct implementation? I'm asking because now I am trying to add state to Oauth requests. But how can I do that?

Frontend code:

useEffect(() => {
    const code = searchParams.get("code");
    const app = searchParams.get("app");
    if (!code || !app) {
      return;
    }
    axios.get(`${BACKEND_URL}/api/v1/oauth/${app}/access?code=${code}`);
}, []);

<Link to={`${BACKEND_URL}/api/v1/oauth/github`}>Login with GitHub</Link>

Backend code:

@app.get('/api/v1/oauth/github')
def github():
    return RedirectResponse(";redirect_uri=FRONTEND_URL/login?app=github&scope=user:email", status_code=307)


@app.get('/api/v1/oauth/github/access')
def github_access(code: str):
    r = requests.post(f";client_secret=CLIENT_SECRET&code={code}")
    ...
    return "token"

Tried to find out answer in chat gpt. But it suggested using variant below. But it looks strange. Is it a good practice?

state_storage = {}

@app.get('/api/v1/oauth/github')
def github():
    state = str(uuid.uuid4())
    state_storage[state] = True
    return RedirectResponse(";redirect_uri=FRONTEND_URL/login?app=github&scope=user:email", status_code=307)

@app.get('/api/v1/oauth/github/access')
def github_access(code: str):
    if state not in state_storage:
        raise HTTPException(status_code=400)
    
    del state_storage[state]
    
    r = requests.post(f";client_secret=CLIENT_SECRET&code={code}")
    ...
    return "token"