composer install- Copy 
config-sample.phptoconfig.phpand fill in yourPartner ID,Partner Secret,Client ID,Client Secret, andMerchant ID.Terminal IDis only applicable for POS merchants. - For One-Time Charge, your url will be 
https://[HOST_NAME]/gp-php-sdk-sample/onetimecharge/and your redirect_uri will behttps://[HOST_NAME]/gp-php-sdk-sample/onetimecharge/complete.php. - For Tokenization, your url will be 
https://[HOST_NAME]/gp-php-sdk-sample/tokenization/and your redirect_uri will behttps://[HOST_NAME]/gp-php-sdk-sample/tokenization/charge.php. - You will need to whitelist your server URL on the GP Developer Platform.
 - For POS Merchant Present QR, your sample HTML page with the QR Code will be 
https://[HOST_NAME]/gp-php-sdk-sample/pos/merchant_present.php.