When modifying the virtual port channel (vPC) domain configuration on a Cisco Nexus 9000 Series Switch using Session Manager, the correct steps involve: 1. Creating a checkpoint: - The checkpoint command is used to create a rollback point before applying the new configuration. This helps in restoring the previous configuration if needed. 2. Applying the configuration: - The commit command is used to apply the changes from the Session Manager to the running configuration, ensuring the new vPC domain settings take effect. These commands ensure that the configuration is valid and safely applied to the switch without disrupting operations.