Getting Wazuh Agent key from Wazuh Server

 TOKEN=$(curl -u "<username>:<password>" -k -X GET "https://<hostname or ip address>:<port number>/security/user/authenticate?raw=true")

curl -k -X POST -d '{"name":"<agentname>"}' "https://<hostname or ip address>:<port number>/agents?pretty=true" -H "Content-Type:application/json" -H "Authorization: Bearer $TOKEN"

Kibana: NoShardsAvailable Error Solved

 Most likely your Kibana shards are not allocated. 

You can check if some or all of your shards are UNASSIGNED using curl -XGET <host>:9200/_cat/shards?v.

In Dev Tools in Kibana:

GET /_cat/shards?v

I have deleted the UNASSIGNED Status index from Kibana Now the Error is resolved