Ignore those boring people who step on you. Didn’t you clearly say that you are a novice? Set up a cross-domain header on a public php page (such as a configuration page)

    // 指定允许其他域名访问,*为任意.  
    header('Access-Control-Allow-Origin:*');  
    // 响应类型,方便ajax等跨  
    header('Access-Control-Allow-Methods:POST');  
    // 响应头设置  
    header('Access-Control-Allow-Headers:x-requested-with,content-type');  

Add a line to index.php in the root directory of the website:

header('Access-Control-Allow-Origin:*');//设置允许跨域

People nowadays are so incompetent and their own level is not that good. They also like to give negative marks to others and express their condolences to the original poster.

You don’t even understand html, I suggest you learn the basics first.
Search on Baidu and set the header in php

Remember not to produce any output before the header is executed

Apache (.htaccess)：

Header set Access-Control-Allow-Origin "*"

Nginx：

add_header Access-Control-Allow-Origin *;

PHP：

header('Access-Control-Allow-Origin:*');