You can't use a code signing certificate for HTTPs. You need a separate TLS certificate instead.
See: Code Signing Certificates vs TLS/SSL Certificates: Everything You Need to Know
You can use OpenSSL or other similar tools to create a TLS certificate that is usable with HTTPS. Self-signed just means that the certificate is signed with its own private key instead of from a trusted CA (certificate authority).
See: Code Signing Certificates vs TLS/SSL Certificates: Everything You Need to Know
You can use OpenSSL or other similar tools to create a TLS certificate that is usable with HTTPS. Self-signed just means that the certificate is signed with its own private key instead of from a trusted CA (certificate authority).