title: Why is this endpoint getting a Access-Control-Allow-Origin error?
body: <p>I'm struggling to understand why this request is giving me a CORS error.  I believe I have both the server and client setup to consume the endpoint properly.  I can make the same request with postman and it works, so I think there is something I'm doing wrong with JS.  The server is using Fastapi, a python framework.  The client is Vue but the request uses Axios (which is Javascript).  Any insight would be appreciated. </p>
  
  <p>Server Settings</p>
  
  <pre><code>app = FastAPI(title="OptionStrats",
      description="For fun fin-trial",
      version="0.0.1",)
  
  origins = ["*", "http://localhost:8080/"]
  
  app.add_middleware(
      CORSMiddleware,
      allow_origins=origins,
      allow_credentials=True,
      allow_methods=["*"],
      allow_headers=["*"],
  )
  </code></pre>
  
  <p>Client Request</p>
  
  <pre><code>axios({
    method: "post",
    url: "http://optionstrats.com/backtest",
    headers: {
      common: {
        "Accept": "application/json",
        "Content-Type": "application/x-www-form-urlencoded"
      },
      "Access-Control-Allow-Origin": "*"
    },
    data: request_dict,
    crossDomain: true
  })
  .then(response =&gt; {
    console.log("backtest response", response);
  })
  .catch(error =&gt; {
    console.log(error);
  });
  </code></pre>
  
  <p>Logs</p>
  
  <pre><code>Starting Request 
  Object { url: "http://optionstrats.com/backtest", method: "post", data: {…}, headers: {…}, transformRequest: (1) […], transformResponse: (1) […], timeout: 0, adapter: xhrAdapter()
  , xsrfCookieName: "XSRF-TOKEN", xsrfHeaderName: "X-XSRF-TOKEN", … }
  Backtest.vue:464
  Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://optionstrats.com/backtest. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).
  
  Error: "Network Error"
  createError createError.js:16
  handleError xhr.js:81
  </code></pre>
  
  <p>I'm explicitly including Access-Control-Allow-Origin in the axios request headers but it seems to not be understood.  What am I doing wrong?  Thanks.</p>