Bicep: deploy a Service Bus Queue while the Service Bus in another resource group

I have a LA deployment that require adding a SB queue. However the the SB is located in another resource group than the LA.

So, when I call the existing the SB I use the following code:

resource serviceBusNamespace 'Microsoft.ServiceBus/namespaces@2017-04-01' existing = {
  name: serviceBusName
  scope: resourceGroup(serviceBusRg)
}

and the queue code:

resource serviceBusNamespaceName_serviceBusQueue 'Microsoft.ServiceBus/namespaces/queues@2024-01-01' = {
  parent: serviceBusNamespace
  name: serviceBusQueueName  
  properties: {
    lockDuration: 'PT5M'
    maxSizeInMegabytes: 1024
    requiresDuplicateDetection: true
    requiresSession: false
    defaultMessageTimeToLive: 'P14D'
    deadLetteringOnMessageExpiration: true
    enableBatchedOperations: true
    duplicateDetectionHistoryTimeWindow: 'PT30M'
    maxDeliveryCount: 10
    status: 'Active'
    autoDeleteOnIdle: 'P10675199DT2H48M5.4775807S'
    enablePartitioning: false
    enableExpress: false
  }
}

When I have the scope written in the SB name space, I am getting an error that:

A resource's computed scope must match that of the Bicep file for it to be deployable. This resource's scope is computed from the "scope" property value assigned to ancestor resource "serviceBusNamespace". You must use modules to deploy resources to a different scope.

So, what is the solution for this problem?

Thank you in advance

A deployment is tied to a resource group (default scope). If you want to deploy a resource in another resource group, you need to create a new deployment. In bicep this is done using module (modules convert to inner/sub deployment):

1. Create a module to create the servicebus queue:

//servicebus-queue.bicep
param serviceBusName string
param serviceBusQueueName string

// get a reference to an existing resource
resource serviceBusNamespace 'Microsoft.ServiceBus/namespaces@2017-04-01' existing = {
  name: serviceBusName
}

resource serviceBusNamespaceName_serviceBusQueue 'Microsoft.ServiceBus/namespaces/queues@2024-01-01' = {
  parent: serviceBusNamespace
  name: serviceBusQueueName  
  properties: {
    lockDuration: 'PT5M'
    maxSizeInMegabytes: 1024
    requiresDuplicateDetection: true
    requiresSession: false
    defaultMessageTimeToLive: 'P14D'
    deadLetteringOnMessageExpiration: true
    enableBatchedOperations: true
    duplicateDetectionHistoryTimeWindow: 'PT30M'
    maxDeliveryCount: 10
    status: 'Active'
    autoDeleteOnIdle: 'P10675199DT2H48M5.4775807S'
    enablePartitioning: false
    enableExpress: false
  }
}

2. Invoke this module from your main bicep with a different scope:

// main.bicep
param serviceBusRg string
param serviceBusName string
param serviceBusQueueName string

// Create SB queue in another resource group
module  servicebusQueue 'servicebus-queue.bicep' = {
  // specify scope to deploy the queue in another resource group
  scope: resourceGroup(serviceBusRg) 
  params: {
    serviceBusName: serviceBusName
    serviceBusQueueName: serviceBusQueueName
  }
}