Make an SSH connection to the server running the API Gateway and select R) Reboot the CA API Gateway appliance (apply the new configuration).

Welcome to the CA API Gateway - 9.3.00
running on Red Hat Enterprise Linux Server release 6.10 (Santiago)

This user account allows you to configure the appliance
What would you like to do?

 1) Configure system settings
 2) Display CA API Gateway configuration menu
 3) Use a privileged shell (root)
 4) Change the Master Passphrase
 5) Display Remote Management configuration menu
 6) Manage HSM
 7) Display CA API Gateway Enterprise Service Manager configuration menu
 8) Display Patch Management menu
 9) Display Log Viewing menu
 R) Reboot the CA API Gateway appliance (apply the new configuration)
 X) Exit (no reboot)

Please make a selection: 

When prompted "are you sure", type y and press enter.

Are you sure you want to reboot the CA API Gateway? [y/n]: