macOS: Import .p12 certificate into the keychain via command line

I'm trying to import .p12 certificate into the keychain on my mac via bash script. So far, I've been trying:

1. sudo security import command. It returns that import was successful but, in fact, it never gets imported into any keychain.
2. sudo security add-certificates -k /Library/Keychains/System.keychain certificate.p12 it throws the following error:

Password: SecCertificateCreateFromData: Unknown format in import.

The only thing that worked for me was the .cer format via this command: sudo security add-certificates -k /Library/Keychains/System.keychain certificate.cer. It does import the certificate into the keychain and I can see it in the keychain access.

But I only have .p12 certificates. Could anyone help me with that one, please?