Android Question Use of the Billing library and surrounding areas

[toro1950]

Good day everyone, I'm trying to list my app on the Google Play Console and would like to sell it
through an annual subscription with automatic renewal, including a one-week free trial.
So I should use the Billing library, but I don't quite understand how it works. What's the BILLING_KEY constant,
the license? I think I found it, it's 392 characters long, is that normal?
What is the ADS_SDK_ID constant, and where can I find it? I think more than a few of you have experience with this,
so I'd appreciate some explanations, both for the library and the subscription. I downloaded the example
of the library, and in it I find the subtitle below, which I don't understand what it's for; it seems to remove ads,
but which ones? Is ADS_SDK_ID an array? What data is inside? I'm sorry, but I'm really clueless.

Sub btnRemoveAds_Click
    'make sure that the store service is connected
    Wait For (billing.ConnectIfNeeded) Billing_Connected (Result As BillingResult)
    If Result.IsSuccess Then
        'get the sku details
        Dim sf As Object = billing.QuerySkuDetails("subs", Array(ADS_SDK_ID))
        Wait For (sf) Billing_SkuQueryCompleted (Result As BillingResult, SkuDetails As List)
'        If Result.IsSuccess And SkuDetails.Size = 1 Then
'            Result = billing.LaunchBillingFlow(SkuDetails.Get(0))
'            If Result.IsSuccess Then Return
'        End If
        If Result.IsSuccess Then
            If SkuDetails.Size > 0 Then
                Dim offers As List = SkuDetails.Get(0).As(JavaObject).RunMethod("getSubscriptionOfferDetails", Null)
                Dim offer As JavaObject = offers.Get(0)
                Dim OfferToken As String = offer.RunMethod("getOfferToken", Null)
'                Result = billing.LaunchBillingFlow(SkuDetails.Get(0))
                Result = LaunchBillingFlow(billing, SkuDetails.Get(0), OfferToken)
                If Result.IsSuccess Then Return
            Else
                ToastMessageShow("Error SKU not found", True)
                Return
            End If
        End If
    End If
    ToastMessageShow("Error starting billing process", True)
End Sub

 

[Erel]

What is the ADS_SDK_ID constant

This is the product id that you added in Google Play developer console.