Hello there,
Please make sure you have uploaded the file inside the 'htdocs' directory of that domain and that you are typing the url correctly as servers are case sensitive (e.g. test.jpg is not the same as Test.jpg).
In case that none of these above apply to your case you are welcome to open a ticket on https://support.ifastnet.com as the support team can access your account and help you troubleshoot your issue.
Also moved this topic under the correct category