I solved the problem, but I do not know what’s going on. I address the process that I did in the past two days.
Firstly, I upgraded my Mac from Sierra to HighSierra, so I was not sure that would bother or not.
And then, I reinstalled my mac, because I thought install with apache may affect this or not.
All PHP packages were checked in php.ini and php7.1 was linked with httpd as well.
After that, I did all check. For example, I ran PHP for connecting to Mongodb in the script, ran Python for the double-check for PHP and ran my website.
However, it still failed. After that, I stopped the listening and restarted it. IT WORKED!
I guess maybe there is no need to reinstall HighSierra. All you need to do is to restart the listening like below in web folder.