The Server Key tab provides a way to select and generate the server certificate.
Here you can select an X.509 certificate to be used to provide the identity of the server and support the SSH connections. You can use certificates stored in the User/Machine certificate stores in Windows as well as certificates stored in .PFX, .PEM, or .PPK files.
By default a test certificate is already configured. Before moving to production it is strongly recommended that you replace this test certificate.