trying to congifure ci not to push to container registry when not on main branch

.drone.yml

@@ -41,6 +41,9 @@ steps:
       - docker build -t $REGISTRY/$OWNER/$IMAGE:$TAG .
 
   - name: container publish
+    trigger:
+      branch:
+      - main
     image: registry.gitlab.com/role_unit/role_unit_containers:build
     privileged: true
     volumes: