This is just what works for me and I am writing just to remind me what I have
done when I will forget what I have done.

If it doesn't work I am sure you're going to find the solution

windows + Xampp solution:

1. go to "https://curl.se/docs/caextract.html" and download "cacert.pem"
2. Put it in this directory "C:\xampp\php\extras\ssl\cacert.pem"
3. go to "C:\PHP\php.ini" and put those two lines:
		- curl.cainfo = "C:\xampp\php\extras\ssl\cacert.pem"
        - openssl.cafile="C:\xampp\php\extras\ssl\cacert.pem"

All of the answers are correct ; but the most important thing is You have to find the right php.ini file. check this command in cmd " php --ini " is not the right answer for finding the right php.ini file.

if you edit

curl.cainfo ="PATH/cacert.pem"
and check

var_dump(openssl_get_cert_locations()); 
then curl.cainfo should have a value. if not then that's not right php.ini file;

*I recommend you to search *.ini in wamp/bin or xxamp/bin or any server you use and change them one by one and check it. *

windows & Wamp solution:

1. go to "https://curl.se/docs/caextract.html" and download "cacert.pem"
2. Put it in this directory "C:\wamp64\cacert.pem"
3. go to "C:\wamp64\bin\php\YOUR_PHP_VERSION\php.ini" and put those two lines:
		- curl.cainfo = "C:\wamp64\cacert.pem"
        - openssl.cafile="C:\wamp64\cacert.pem"