Validate and log purchase

Follow the instructions according to your operating system.

Calling validateAndSendInAppPurchase automatically generates an af_purchase in-app event, so you don't need to send this event yourself.
The validate purchase response is triggered in the AppsFlyerTrackerCallbacks.cs class.

// for Android 
`void validateAndSendInAppPurchase(AFPurchaseDetailsAndroid details, Dictionary<string, string> additionalParameters, MonoBehaviour gameObject)`
// for iOS 
`void validateAndSendInAppPurchase(AFSDKPurchaseDetailsIOS details, Dictionary<string, string> extraEventValues, MonoBehaviour gameObject)`

using UnityEngine.Purchasing;
using AppsFlyerSDK;

public class AppsFlyerObject : MonoBehaviour, IAppsFlyerValidateAndLog
{

    public static string kProductIDConsumable = "com.test.cons";

    void Start()
    {
        AppsFlyer.initSDK("devKey", "devKey");
        AppsFlyer.startSDK();
    }

    public PurchaseProcessingResult ProcessPurchase(PurchaseEventArgs args)
    {
        string prodID = args.purchasedProduct.definition.id;
        string price = args.purchasedProduct.metadata.localizedPrice.ToString();
        string currency = args.purchasedProduct.metadata.isoCurrencyCode;

        string receipt = args.purchasedProduct.receipt;
        var recptToJSON = (Dictionary<string, object>)AFMiniJSON.Json.Deserialize(product.receipt);
        var receiptPayload = (Dictionary<string, object>)AFMiniJSON.Json.Deserialize((string)recptToJSON["Payload"]);
        var transactionID = product.transactionID;

        if (String.Equals(args.purchasedProduct.definition.id, kProductIDConsumable, StringComparison.Ordinal))
        {
#if UNITY_IOS

            if(isSandbox)
            {
                AppsFlyeriOS.setUseReceiptValidationSandbox(true);
            }

            AFSDKPurchaseDetailsIOS details = AFSDKPurchaseDetailsIOS.Init(prodID, price, currency, transactionID);

            AppsFlyeriOS.validateAndSendInAppPurchase(details, null, this);
#elif UNITY_ANDROID

        AFPurchaseDetailsAndroid details = new AFPurchaseDetailsAndroid(AFPurchaseType.Subscription, "token", prodID, price, currency);

        AppsFlyerAndroid.validateAndSendInAppPurchase(
        details,
        null, 
        this);
#endif
        }

        return PurchaseProcessingResult.Complete;
    }

    public void onValidateAndLogComplete(string result)
    {
        AppsFlyer.AFLog("onValidateAndLogComplete", result);
        Dictionary<string, object> validateAndLogDataDictionary = AppsFlyer.CallbackStringToDictionary(result);
    }

    public void onValidateAndLogFailure(string error)
    {
        AppsFlyer.AFLog("onValidateAndLogFailure", error);
        Dictionary<string, object> validateAndLogErrorDictionary = AppsFlyer.CallbackStringToDictionary(error);
    }

}

Receipt validation [Legacy]

For Receipt Validation, follow the instructions according to your operating system.

Notes
Calling validateReceipt automatically generates an af_purchase in-app event, so you don't need to send this event yourself.
The validate purchase response is triggered in the AppsFlyerTrackerCallbacks.cs class.

void validateAndSendInAppPurchase(string productIdentifier, string price, string currency, string tranactionId, Dictionary<string, string> additionalParameters, MonoBehaviour gameObject)

//To get the callbacks
//AppsFlyer.createValidateInAppListener ("AppsFlyerTrackerCallbacks", "onInAppBillingSuccess", "onInAppBillingFailure");
AppsFlyer.validateReceipt(string publicKey, string purchaseData, string signature, string price, string currency, Dictionary additionalParametes);

using UnityEngine.Purchasing;
using AppsFlyerSDK;

public class AppsFlyerObject : MonoBehaviour, IStoreListener, IAppsFlyerValidateReceipt
{

    public static string kProductIDConsumable = "com.test.cons";

    void Start()
    {
        AppsFlyer.initSDK("devKey", "devKey");
        AppsFlyer.startSDK();
    }

    public PurchaseProcessingResult ProcessPurchase(PurchaseEventArgs args)
    {
        string prodID = args.purchasedProduct.definition.id;
        string price = args.purchasedProduct.metadata.localizedPrice.ToString();
        string currency = args.purchasedProduct.metadata.isoCurrencyCode;

        string receipt = args.purchasedProduct.receipt;
        var recptToJSON = (Dictionary<string, object>)AFMiniJSON.Json.Deserialize(product.receipt);
        var receiptPayload = (Dictionary<string, object>)AFMiniJSON.Json.Deserialize((string)recptToJSON["Payload"]);
        var transactionID = product.transactionID;

        if (String.Equals(args.purchasedProduct.definition.id, kProductIDConsumable, StringComparison.Ordinal))
        {
#if UNITY_IOS

            if(isSandbox)
            {
                AppsFlyeriOS.setUseReceiptValidationSandbox(true);
            }

            AppsFlyeriOS.validateAndSendInAppPurchase(prodID, price, currency, transactionID, null, this);
#elif UNITY_ANDROID
        var purchaseData = (string)receiptPayload["json"];
        var signature = (string)receiptPayload["signature"];
        AppsFlyerAndroid.validateAndSendInAppPurchase(
        "<google_public_key>", 
        signature, 
        purchaseData, 
        price, 
        currency, 
        null, 
        this);
#endif
        }

        return PurchaseProcessingResult.Complete;
    }

    public void didFinishValidateReceipt(string result)
    {
        AppsFlyer.AFLog("didFinishValidateReceipt", result);
    }

    public void didFinishValidateReceiptWithError(string error)
    {
        AppsFlyer.AFLog("didFinishValidateReceiptWithError", error);
    }

}