使用BigCommerce的“/v3/payments/gateway”接口来获取已安装付款方式的列表，并通过比较两个列表来找出未安装且不返回的付款方式。

以下是使用PHP语言实现此解决方案的示例代码：

// Get a list of installed payment gateways $installedGatewaysRequestUrl = 'https://api.bigcommerce.com/stores/{store_hash}/v3/payments/gateway'; $installedGatewaysRequestHeaders = array( 'Authorization: Bearer '.$accessToken, 'Accept: application/json', 'Content-Type: application/json' ); $installedGatewaysResponse = json_decode(curlGetRequest($installedGatewaysRequestUrl, $installedGatewaysRequestHeaders), true); $installedGateways = array(); foreach ($installedGatewaysResponse['data'] as $installedGateway) { $installedGateways[] = $installedGateway['name']; }

// Get the list of accepted payment methods from the API response $acceptedPaymentMethodsResponse = json_decode($apiResponse, true); $acceptedPaymentMethods = array(); foreach ($acceptedPaymentMethodsResponse['data']['paymentMethods'] as $paymentMethod) { $acceptedPaymentMethods[] = $paymentMethod['name']; }

// Find which payment methods are not installed on the store $notInstalledPaymentMethods = array_diff($acceptedPaymentMethods, $installedGateways); ?>

请注意，此示例代码供参考，中间需要您填写相应的变量值，并根据实际需求进行修改。同时，代码中涉及到的函数“curlGetRequest”和变量“$apiResponse”需要您自行实现和定义。