How to test Redeem Code flow?

Hello,

I implement redeem code inApp with this code :

    let paymentQueue = SKPaymentQueue.default()

        if #available(iOS 14.0, *) {                     paymentQueue.presentCodeRedemptionSheet()

                }

        }

Before this I make every setup about subscription in my application. Now I just want to implement Redeem Code in-app.

And generate 1 redeem code for test in AppstoreConnect. I'm logged in with sandbox account in my application and enter that redeem code, I got : "The code you entered could not be found." at the top of RedeemCode screen.

I wait 24h and again same error.

Can someone to help me about testing of Redeem Codes and check my implementation?