Welcome to the Community and thanks for reaching out to us. Hope you don't mind us replying in English!
If you're still experiencing this. You can start off by checking your inbox to see if you've received a confirmation email from SheerID. You should be able to apply the discount on your account by clicking the link in that email.
If that doesn't solve the issue, feel free to take a look at this Spotify Answer that has some other steps that you can try.
Keep us in the loop and don't hesitate to get back to us if you have any other questions.
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