I found the key submission box to decrypt my form results, but it won't upload

What am I doing wrong? 

Once you the "jotform.key" is in the upload field, you just need to click the "exit" button.

Please check this user guide for more information about Form Encryption: https://www.jotform.com/help/344-Encrypted-Forms-and-How-to-Use-Them.

Hope that helps. Thank you.