Hi, dadak113,
It looks like you subscribed to Discord through the App Store on an iOS device, but are looking for them through the Discord application on a Windows PC. If you open the Discord app on the iOS device you subscribed with, do you see the subscription there? If you do, make sure you are signed into the same Discord account on all of your devices as the one on your iOS device.
If you check your iTunes and App Store subscriptions through iTunes on your Windows PC, does the subscription appear? How about if you check on your iOS device again? You can use the steps in If you want to cancel a subscription from Apple - Apple Support to help view the subscription (even if you're not intending to cancel it. The steps in this article will show you how to view on your different devices).
If you're still not seeing the subscription, you can report a problem with it by visiting Report A Problem, signing in with the Apple ID used to purchase the subscription, and following the on-screen prompts.
If you still need help after that, don't hesitate to respond back.
Cheers!