This is the code to check my VIP user status; I placed it in my application. My user is not considered a VIP user after purchasing my in-app package "iap_lifetime". I'm not sure if there's a problem with my code. I called acknowledgePurchase after receiving a purchase callback from the Listener billingClient.

val acknowledgeParams =
    AcknowledgePurchaseParams.newBuilder().setPurchaseToken(purchase.purchaseToken)
        .build()

client.acknowledgePurchase(acknowledgeParams) { billingResult: BillingResult ->
    runOnUiThread {
        processingPurchaseTokens.remove(purchase.purchaseToken)
        if (billingResult.responseCode == BillingClient.BillingResponseCode.OK) {
            val productId = purchase.products.firstOrNull() ?: ""
            AdAnalyticsHelper.trackIapRevenue(purchase, productDetailsMap[productId])
        } else {
            showToast("Acknowledge failed: ${billingResult.debugMessage}")
        }
        finalizeVipActivation(grant)
    }
}

fun checkSubscription() {
    try {
        val billingClient = BillingClient.newBuilder(this)
            .enablePendingPurchases()
            .setListener { _, _ -> }
            .build()

        billingClient.startConnection(object : BillingClientStateListener {

            override fun onBillingServiceDisconnected() {
            }

            override fun onBillingSetupFinished(billingResult: BillingResult) {
                if (billingResult.responseCode != BillingClient.BillingResponseCode.OK) {
                    VipManager.setVip(false)
                    return
                }
                // Check SUBS
                billingClient.queryPurchasesAsync(
                    QueryPurchasesParams.newBuilder()
                        .setProductType(BillingClient.ProductType.SUBS)
                        .build()
                ) { subsResult, subsList ->
                    var isVip = false
                    if (subsResult.responseCode == BillingClient.BillingResponseCode.OK) {
                        isVip = subsList.any { purchase ->
                            purchase.purchaseState == Purchase.PurchaseState.PURCHASED &&
                                    purchase.products.isNotEmpty()
                        }
                    }

                    if (!isVip) {
                        billingClient.queryPurchasesAsync(
                            QueryPurchasesParams.newBuilder()
                                .setProductType(BillingClient.ProductType.INAPP)
                                .build()
                        ) { inAppResult, inAppList ->
                            if (inAppResult.responseCode == BillingClient.BillingResponseCode.OK) {
                                isVip = inAppList.any { purchase ->
                                    purchase.purchaseState == Purchase.PurchaseState.PURCHASED &&
                                            purchase.products.contains("iap_lifetime")
                                }
                            }
                            VipManager.setVip(isVip)
                        }
                    } else {
                        VipManager.setVip(true)
                    }
                }
            }
        })
    } catch (_: Exception) {
    }
}