Splunk Add-on for Unix and Linux - can't connect to server

[Herman]

Trying to monitor the performance data on MacOS and downloaded Splunk Add-on for Unix and Linux 

After clicking 'save' for setting on Splunk Enterprise Web, it shows the page that says 'Safari Can't Connect to the Server 

Safari can't open the page "localhost:8000/en-US/app/Splunk_TA_nix/ta_nix_configuration" because Safari can't connect to the server "localhost".'

Please find the attached for reference

Any help would be appreicated! Thanks!

ref:

https://docs.splunk.com/Documentation/AddOns/released/UnixLinux/About

https://splunkbase.splunk.com/app/833/

https://lantern.splunk.com/hc/en-us/articles/360048491734-Operating-system-performance-data-