How to restrict attachment file attachments based on extensions in ServiceNow [Paris]

Sometimes you might want to prevent certain file extensions from being uploaded to ServiceNow. You can do that here in this property.

Per ServiceNow,
Use this property to improve security by preventing users from uploading harmful files, such as viruses, as attachments. Also, this capability can prevent the use of incompatible filetypes. For example, Internet Explorer does not support icons in .png format. This property does not restrict files based on the actual file type, but only based on the extension.