Advice on viewing encrypted WhatsApp files/ messages

Could you please give me some advice on my issue. I have backup crypt14 files I have saved to my PC and I’m trying to view them on WhatsApp viewer. I am asked to upload the key file which I do not have, (however I have a screenshot of the 60 digit encryption key of a particular chat in WhatsApp). Are there any other decryption tools I can use to view my backups without the key file?

Thanks