What certificate to use along with neo4j@code-signer

I'm currently developing a graph app for neo4j desktop. From what i figured out, app should be signed with neo4j@code-signer (which utilizes node-forge i presume). It needs a certificate and private key (and password probably).

What i can't figure out is, what kind of certificate is actually needed?

1. I signed my app with self-signed certificate which produced a big untrusted warning in neo4j desktop (touche, i should have known).
2. I used my ssl key which enabled my HTTPS, but this produced an error in neo4j desktop:

Certificate keyUsage or basicConstraints conflict or indicate that the certificate is not a CA. If the certificate is the only one in the chain or isn't the first then the certificate must be a valid CA.

Both options did produce signature.pem file.

Do i need to buy a Code Signing Certificate for this? If so, standard or EV?

Any help would be greatly appreciated!

Maybe this is going to help somebody: There wasn't any issue with my certificates.

I got an answer from neo4j offical, that they are (at the time being) signing apps internaly, and that there is no automated way to do this (yet).