.htaccess to add CORS to your website

.htaccess

# Add these three lines to CORSify your server for everyone.

Header set Access-Control-Allow-Origin "*"
Header set Access-Control-Allow-Methods "GET,PUT,POST,DELETE"
Header set Access-Control-Allow-Headers "Content-Type, Authorization"

ReadMe.md

CORSify a folder in Apache

Add the above three lines to an .htaccess file to enable CORS for that folder and its subfolders. Of course, you could also add this to the httpd.conf file if you have access.

###Notes:

• Ensure that the mod_headers Apache Module is enabled.
• This will open things up pretty grandly. This may or may not be what you want.

###Disclaimer

• Do at your own risk, etc. etc.
• My Apache-fu is weak, so there may well be a better solution.

where to add this code ? on the very top of the .htaccess file

This will leave your website open to security vulnerabilities. Any, read that correctly, ANY site will be able to return data to your site, and if your site doesn't check to see if it is what it expects (sorry for the mouth full), it will run any code passed back. Don't leave open doors for intruders.

For CORS, even though the documentation states to use 'SET', it is recommended to use 'ADD' as that will work on most systems. If you notice that when you use the above code and you are still receiving the pre-flight or CORS errors, change 'set' to 'add' and you will most likely be fine.

If this problem can't be solved by .htaccess, then try to put in your PHP file next:
header("Access-Control-Allow-Origin: *");

If this problem can't be solved by .htaccess, then try to put in your PHP file next: header("Access-Control-Allow-Origin: *");

I don't understand. Which PHP file?