Helper/Config.php
public function getAdditionalCheckoutButtonClass($storeId = null)
    {
        return $this->getScopeConfig()->getValue(
            self::XML_PATH_ADDITIONAL_CHECKOUT_BUTTON_CLASS,
            ScopeInterface::SCOPE_STORE,
            $storeId
        );
    }
public function getAdditionalCheckoutButtonClass($storeId = null)
    {
        return $this->getScopeConfig()->getValue(
            self::XML_PATH_ADDITIONAL_CHECKOUT_BUTTON_CLASS,
            ScopeInterface::SCOPE_STORE,
            $storeId
        );
    }
public function getAdditionalCheckoutButtonClass ( $ storeId = null ) { return $ this -> getScopeConfig ( ) -> getValue ( self :: XML_PATH_ADDITIONAL_CHECKOUT_BUTTON_CLASS , ScopeInterface :: SCOPE_STORE , $ storeId ) ; }
Get additional checkout button class

@param int|string $storeId

@return string
Get additional checkout button class