Most likely, we could not deliver a payment notification to your site (we are making 5 attempts to send), you need to try to send a notification manually, for this you need to find the payment and click the "Send IPN" button, in case of an error it will be indicated with a brief instruction for its elimination. In case of an unsuccessful answer, contact your developer for help. Another possible reason is that your Firewall is blocking the access of our notification server to your website, for this you need to add our notification server IPs to the whitelist, you can find our IPs on the page - go. If the notification is not delivered due to underpayment, this means your merchant does not have permission to accept any amount as a successful payment. In this case, you have to make the accrual in your system manually. If you want to avoid such behaviour of the system in the future, you must make sure that your script supports the crediting of arbitrary amounts and allow Accept any amount in the merchant's settings.