Kibana Error to connect to another server

When I configure kibana to another cluster server like below:

(I only changed below from default kibana.yml)

Any idea why?? My side or server side problem?

i keep getting below errors:
log [16:57:43.700] [error][elasticsearch] Request error, retrying -- connect ETIMEDOUT
log [16:57:46.675] [warning][elasticsearch] Unable to revive connection:
log [16:57:46.676] [warning][elasticsearch] No living connections

Please don't post multiple threads on the same issue.

See How Can I use Kibana to see indices in another ES Cluster?