Android Question problem with " CallSubDelayed(FirebaseMessaging, "SubscribeToTopics")"

'Starter service
Sub Process_Globals

End Sub

Sub Service_Create
   CallSubDelayed(FirebaseMessaging, "SubscribeToTopics")
End Sub

Sub Process_Globals
    Public analytics As FirebaseAnalytics
    
   Private fm As FirebaseMessaging
End Sub

Sub Service_Create
   fm.Initialize("fm")
    CallSubDelayed(FirebaseMessaging, "SubscribeToTopics") ' why is this one red
    
End Sub

Public Sub SubscribeToTopics
   fm.SubscribeToTopic("general") 'you can subscribe to more topics
End Sub

Sub Service_Start (StartingIntent As Intent)
   If StartingIntent.IsInitialized And fm.HandleIntent(StartingIntent) Then Return
End Sub

Sub fm_MessageArrived (Message As RemoteMessage)
   Log("Message arrived")
   Log($"Message data: ${Message.GetData}"$)
   Dim n As Notification
   n.Initialize
   n.Icon = "icon"
   n.SetInfo(Message.GetData.Get("title"), Message.GetData.Get("body"), Main)
   n.Notify(1)
End Sub

Sub Service_Destroy

End Sub

ub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

End Sub

Sub Globals
    'These g
End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    Activity.LoadLayout("Layout1")

End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub