Dear @Azeemkm20,

We raised a similar case and please find below the answer we get from Support in October 2022 for on-prem deployments:

Run the following command to see if the environment variable is in place for the running service:
sudo cat /proc/`ps -ef|grep dotnet|grep Play|grep -v grep|awk '{print $2}'`/environ|strings|grep CLIENT_ADDRESS

If it returns no results, then you will need to add the variable using the following command: 
sudo systemctl set-environment CLIENT_ADDRESS=YOURSERVERADDRESS

Then restart the playbook service with the following command: 
sudo systemctl restart Siemplify.Server.PlaybookActions.service

Then check for the variable again using the same command as above:
sudo cat /proc/`ps -ef|grep dotnet|grep Play|grep -v grep|awk '{print $2}'`/environ|strings|grep CLIENT_ADDRESS

At this point, you should see the variable in the output of the command, and the approval links should have the proper hostname.   This will be rolled into future releases.

Kind regards,
Louis