refundPayment method
Implementation
Future<Map<String, dynamic>> refundPayment(String paymentId) async {
final token = await _getAccessToken();
final url = '$_paymentUrl/$paymentId/refund';
final response = await _dio.post(
url,
options: Options(
contentType: Headers.formUrlEncodedContentType,
headers: {'Authorization': 'Bearer $token'},
),
);
return response.data;
}