Accidentally activated some API which is charging me. I just wanted to activate free tier for study.

[navinray91]

Start VM instance "master"

My First Project

This API method requires billing to be enabled. Please enable billing on project #soy-tube-417711 by visiting https://console.developers.google.com/billing/enable?project=soy-tube-417711 then retry. If you enabled billing for this project recently, wait a few minutes for the action to propagate to our systems and retry.

[Marramirez]

Hello @navinray91,

Take a look at: Free cloud features and trial offer. Your free trial should include $300 credits to explore GCP products and services. The API method that you are calling requires billing. If you are getting charged, it should deduct from your free credits first. 

If you still have questions, you can contact Google Cloud Billing to further look into your case. Hope it helps, thanks!