If the certificate is self-signed, only the server certificate is needed.
The certificate should be in PEM format and it will look the following:
-----BEGIN CERTFICATE----- MIIGfTCCBGWgAwIBAgIJAItB7Cswxl7NMA0GCSqGSIb3DQEBCwUAMCIxIDAeBgNV BAMMF2NvbmV4LmxhYnMudGVyYWRhdGEuY29tMB4XDTIyMDYwOTE5MTM0OFoXDTIz ... -----END CERTFICATE -----
If the certificate is not self-signed, the certificate authority chain should be collected by the party who provided certificate. It may include several certificates.