why can't I customize my code block?

[raccoon-zhang]

It just is showed like this.

while the code is

 // 使用正则表达式将代码块提取出来
            var codeMatches = message.match(/```[\s\S]*?```/g);

            if (codeMatches != null) {
                // 遍历每个代码块
                for (var i = 0; i < codeMatches.length; i++) {
                    var codeBlock = codeMatches[i];

                    // 获取代码类型
                    var codeType = codeBlock.match(/```(\S+)\n/)[1] ? codeBlock.match(/```(\S+)\n/)[1] : null;

                    //创建实例
                    var converter = new showdown.Converter();
        
                    //进行转换
                    var text = converter.makeHtml(codeBlock);
                    // 创建新的代码块元素
                    var codeElement = document.createElement("pre");
                    codeElement.innerHTML = "<code class='language-" + codeType + "'>" + text + "</code>";

                    // 替换文本中的代码块为代码块元素
                    message = message.replace(codeBlock, codeElement.outerHTML);
                }
            }

            innerElement.innerHTML = message

the message I get is

#include <iostream>

int main() {
    std::cout << "Hello, World!" << std::endl;
    return 0;
}

the web is like this