Not able to start grafana server in macOs Catalina

I have installed Grafana using homebrew in my macOs Catalina using the commands
brew update
brew install grafana

Next, I tried starting Grafana server using the command
brew services start grafana

which gives output as

==> Successfully started grafana (label: homebrew.mxcl.grafana)

but on browser, not able to open grafana. getting blank screen. I also checked the ports being listened on in my mac using netstat, but didn’t see any 3000 port being active. So I tried starting grafana-server using the command
/usr/local/opt/grafana/bin/grafana-server
which gives error as

Grafana-server Init Failed: Could not find config defaults, make sure homepath command line parameter is set or working directory is homepath

I also have changed my grafana.ini file (in location /usr/local/etc/grafana/grafana.ini). just removed the , before http_port, and domain properties, but still no luck. what am I missing?