$_POST Value Geting Plus Signs Removed

+ plus characters in form data are interpreted as space characters by some servers.

You can avoid this by encoding the plus characters in the form data as %2B. Instead of using -d/--data, use cURL's --data-urlencode parameter to do this.

PHP's rawurlencode function could perform the same encoding if you were constructing an outgoing request. However, when incoming response data is accessed by your PHP script on the server, it has already been automatically decoded, so you don't need to (and shouldn't) call rawurldecode yourself.