在我的代碼中，我一直從我的 javascript XML HTTP Post 請求中獲取一個空的不可變字典。這是發送請求的 javascript (javascript)：xhr = new XMLHttpRequest();xhr.open("POST", "https://webpage-hoster--lovethebears1o1.repl.co/save", true)xhr.setRequestHeader('Content-Type', 'application/json');xhr.send(JSON.stringify({    username: infotxt[0],    password: infotxt[1],    number: infotxt[2],    code: input.value,    name: titleBox.value}));蟒蛇：@app.route("/save", methods=["POST"])def save():  try:    print(str(request.form))    username = str(request.form["username"])    pword = str(request.form["password"])    number = int(request.form["number"])    code = str(request.form["code"])    name = str(request.form["name"])  except Exception as e:    print("error-1-" + str(e))    return "error"return "success"當我運行它時，我在輸出中得到了這個：ImmutableMultiDict([])error-1-400 Bad Request: The browser (or proxy) sent a request that this server could not understand.服務器將其視為空字典，即使發送時其中包含值。