>To change per-app settings for any application, including Discord, on an iPhone or iPad, go to the Settings app > Accessibility > Per-App Settings. Tap Add App, select Discord from the list, and then customize settings like Display & Text Size to alter the app's appearance or behavior without affecting other applications.
A quick Google search says that for iOS 15+:
>To change per-app settings for any application, including Discord, on an iPhone or iPad, go to the Settings app > Accessibility > Per-App Settings. Tap Add App, select Discord from the list, and then customize settings like Display & Text Size to alter the app's appearance or behavior without affecting other applications.