在gridjs中显示javascript函数的返回值

你好，我是gridjs的新手，有人能帮我吗。我想显示如何使用gridjs将javascript函数中的值返回到表中这是我的代码

HTML

下面是我在Javascript中的函数

let grid_table = new gridjs.Grid({
        pagination: true,
        columns: [ 'Stockholder Address', 'StockholderName', 'Representative', 'Number of shares', 'Registered Area' ],
        server: {
            url: '/api/stockholder?registered=true',
            method: 'GET',
            then: data => data.map(stockholder => [ 
                stockholder.district, 
                stockholder.stockholderName,
                stockholder.representative,
                stockholder.numberOfStock,
                registered_area(stockholder.userID)
            ])
        }
    })

const registered_area = async (userID) =>{
       try{
           let user_response = await fetch('/api/user/details?userID='+userID);
           let user_result = await user_response.json();
           return user_result[0].district;
       }catch(error){
         console.log(error)
       }
 }

此图像必须是预期结果

但目前的结果是这样的

我希望有人能帮我谢谢

const registered_area = async (userID) =>{
       try{
           let user_response = await fetch('/api/user/details?userID='+userID);
           let user_result = await user_response.json();
           return user_result[0].district;
       }catch(error){
         console.log(error)
       }
 }