We have generated a self-signed certificate from SFDC and provided to our client network team which we are expecting them to install at their application to authorize us accessing their application. Network team rejected the certificate with the reason as the certificate has no information on private key.

Based on my research was able to figure out private key should be known by the owner of the certificate which is used by the server to validate against the public key and confirm the identity of the source.

Could someone please guide on how we can get the private key from SFDC as I dont see any interface for the same?