Hi Josh,
After adding ssl_insecure_skip_verify in dashboard and gateway server was still throwing error.
So have tried removing this configuration from dashboard conf only and restarted servers again.
Now both gateway and dashboard are up and running.
But when I am trying to open dashboard on browser, it is getting displayed as not secure site with https://
and while accessing API through postman, gateway is throwing below errors,
http: TLS handshake error from XX.XX.XX.XXX:49524: tls: first record does not look like a TLS handshake