Terraform plugin

Im really strugling with using terraform plugin.

my .drone.yml file:

    image: jmccann/drone-terraform:latest
+   actions:
+     - validate
+     - plan

But every time I got error:

yaml: line 5: could not find expected ‘:’

should I register my plugin in anyway?

I use
GitHub - jmccann/drone-terraform: Drone plugin for triggering Terraform deployments plugin.

Any help would be appreciated!

thanks and regards, pavel