You need to configure GCP Cloud SDK in your command line. It will connect to your GCP Cloud API. After that, you can use the below command to create a firewall rule to your VPC.
$ gcloud compute --project=nadeem-gcp-123456 firewall-rules create NAME --direction=INGRESS --priority=1000 --network=default --action=ALLOW --rules=PROTOCOL:PORT
Hope this helps!!
If you need to know more about Google Cloud, It's recommended to go for Google Cloud architect certification course.