Alternative to DM Actions

Hi,
Currently I use an action to add an instance to an instance group. Since actions are not supported in DM anymore, how can I accomplish the same result in DM itself?

```
resources.append({
'name': resource_name,
'action': 'gcp-types/compute-v1:compute.instanceGroups.addInstances',
'properties': {
'instanceGroup': instance_group_names['instancegroup1'],
'zone': vm1_zone,
'instances': [
{
'instance': '$(ref.' + vm1_name + '.selfLink)'
}
]
}
})
```
Thanks!