Log into the Service Desk Manager application server and browse into the installation folder. Within the root of the folder take a backup of the NX.ENV file and then edit the following variable:
@NX_SERVLET_SERVER_URL=http://servicedeskhostname:8080
Change it to
@NX_SERVLET_SERVER_URL=https://servicedeskhostname:8443
In the example above "servicedeskhostname" would represent the hostname of the ServiceDesk server, and 8443 is the port.
Save the file and recycle services of CA Service Desk Manager for the change to take place.