I am learning Magento and try to create a module can connect with Facebook account via their Facebook ID.
Can you tell me where to put the SDK libary of facebook to whịch folder of magento and how can I config that libary
You have to put that file in lib folder
Eg:
lib/facebook/yourfile.php
to get that file
require_once('facebook/yourfile.php')
You can put the Facebook SDK folder where you want (eg in a vendor/ directory at root), you just need to require_once '/path/to/sdk/folder/autoload.php'; somewhere in your code.