The file type .ppt or .pptx is not uploading

In a jotform I created, there is an option to upload a powerpoint file in the file type ppt or pptx. When I test out the jotfrom and try to upload either a ppt or pptx, I get the following message:

2020 Co...ng.pptx has invalid extension. Only .ppt .pptx are allowed.

Hi, the allowed file types were not listed correctly, we have fixed this for you. The needed to be separated by a comma only:

This is now working on your form:

Let us know if you need more help.