我正在编写javascript文件以将json数据加载到表中，但我遇到了这个错误。请帮忙！

const showHeader= (headers)=>{
const tableArr=headers;
const tableMain=document.getElementById("tablebox");
let rowEle  ='<tr class="header">';
tableArr.forEach(tableRow=>{
        rowEle += `<th class='${String(tableRow).toLowerCase()}'>`+String(tableRow)+'</th>';
    });
    rowEle +='</tr>'
    console.log(rowEle)
    tableMain.innerHTML += rowEle;

}

const showTableOnLoad= (data, check=true)=>{
    if(check)
    showHeader(Object.keys(data[0]).map((headerString)=> headerString.toUpperCase()));
    const tableArr=data;
    const tableMain=document.getElementById("tablebox");
    tableArr.forEach(tableRow=>{
        let rowEle  ='<tr>';
        Object.entries(tableRow).forEach(entry =>{
            const[key,value]=entry;
            rowEle += '<td class="${key}">'+value+'</td>';
        });
        rowEle +='</tr>'
        tableMain.innerHTML += rowEle;
    });
}