Curl - 发送运行php文件的请求

I have a php file in a server, and i want to send a request to run that file via bash script.

If you open the link domain.com/example.php in a browser, the php will run. But if you send the request via curl (from the client computer), sometimes it works, and sometimes it doesn't work (After each request which works, it doesn't work for several seconds):

curl domain.com/example.php

The php contains a single command: shell_exec("mkdir worked"). Sometimes the worked directory is made, sometimes it's not. Tho if you send the request via a browser, every time the worked directory is made.

How to send a request from a client computer via bash to the server, so the server will run the php file (which is located in the server)?

Thanks in advance.