Protect sensitive files with encryption. Only users with the URL will be able to view it. "
This is not encryption - you should change the copy to tell what encryption is used (AES-128 from the info here), even if it's beta. Some more information on that will be welcome.
"Your file is first securely encrypted using a secret key (AES-128) with Javascript on your device. Once it has been encrypted, the encrypted data is uploaded to a NoFile storage server over a secure HTTPS connection preventing any malicious users from seeing what you're uploading (as an extra layer of security).
Only those with the secret key (which is in the URL) will be able to see the correct content and filename - if a single character of the key varies, then the file will be unrecognizable."
You need to set this as your preferred method on the upload page.
A link has also been added to that block to make it easier to find, thanks for pointing it out.