I think there's a typo in the NB6 class, found at https://www.b4x.com/android/forum/threads/nb6-notifications-builder-class-2018.91819/#content.
The ChannelName is never used. Instead Application.LabelName is used as name for the channel.
B4X:
Public Sub Initialize (ChannelId As String, ChannelName As Object, ImportanceLevel As String) As NB6
ctxt.InitializeContext
PendingIntentStatic.InitializeStatic("android.app.PendingIntent")
NotificationStatic.InitializeStatic("android.app.Notification")
common.InitializeStatic("anywheresoftware.b4a.keywords.Common")
Dim jo As JavaObject
SdkLevel = jo.InitializeStatic("android.os.Build$VERSION").GetField("SDK_INT")
If SdkLevel < 23 Then
SupportLevel = S_OLD
Else if SdkLevel >= 26 Then
SupportLevel = S_CHANNEL
Else
SupportLevel = S_BUILDER
End If
If IsOld Then
OldNotification.Initialize
OldNotification.Icon = "icon"
Else if IsChannel Then
ChannelId = ChannelId & "_" & ImportanceLevel
NotificationBuilder.InitializeNewInstance("android.app.Notification$Builder", Array(ctxt, ChannelId))
Dim im As Map = CreateMap("MIN": 1, "LOW": 2, "DEFAULT": 3, "HIGH": 4)
Dim i As Int = im.Get(ImportanceLevel)
Channel.InitializeNewInstance("android.app.NotificationChannel", Array(ChannelId, Application.LabelName, i))
Else
NotificationBuilder.InitializeNewInstance("android.app.Notification$Builder", Array(ctxt))
Dim pm As Map = CreateMap("MIN": -2, "LOW": -1, "DEFAULT": 0, "HIGH": 1)
Dim p As Int = pm.Get(ImportanceLevel)
NotificationBuilder.RunMethod("setPriority", Array(p))
End If
If ImportanceLevel = "DEFAULT" Or ImportanceLevel = "HIGH" Then
SetDefaults(True, True, True)
Else
SetDefaults(False, True, True)
End If
Return Me
End Sub
The ChannelName is never used. Instead Application.LabelName is used as name for the channel.