无法向节点服务器发出post请求

I am building a simple server using Node JS. I am using express for routing. I wanted to test post requests using JQuery, but I have been unable to succeed. I looked up the issue and many responses mentioned a cross-origin issue. I followed every piece of advice on the subject, but I am still unable to make it work. Here is my server code:I am building a simple server using Node JS. I