Turn on the trial mode in LiqPay Business Account. Keys are available on the main page in the ""Get trial API keys"" section. You may use these keys to make trial payments. Examples of keys: sandbox_i33111011000 sandbox_9ydlqKMsZZnmPk6piHLPlqRpqZNXkcYCn7cOh7vM https://www.liqpay.ua/documentation/api/sandbox