How to generate a key fingerprint to my PPA (key missing)

I create a new PPA (https://launchpad.net/~adimira/+archive/ubuntu/adimira-os) currently with specific packages copied from other PPAs because of conflict generated by other packages from them.

But since it appears that Launchpad will only generate a signing key after I upload a source package to it, how can I trigger the key generation on my case?

Thank you!