How can I re-download my private key?

I used my private key so I'm able to access submissions, but another person in our company is needing to see the submissions, and I already deleted the key. I didn't know that everyone who wants to see submissions would need to have the same private key.

As encryption keys are per account you can try go to a form > select preferences > advanced settings > encrypt form data > yes:

When the pop-up screen shows up, please select "create encryption key for me":

Let us know if we can assist you further.