To install the extension:
- Log in the ftp, and then go to Magento 2 root folder (generally present under the public_html folder).
- Create a new folder named code under the app folder; under code folder, create a folder named Ced.
- Upload or Drag and Drop app/code/Ced/Overstock directory.
- After successfully uploading the directory, the extension will be installed/upgraded.
- Now run the following upgrade command in cmd
php bin/magento setup:upgrade.