Please find the below step to clear the caches of the System app or third-party app.
Method 1:
realme UI 5.0 & 4.0 & 3.0: Settings > Apps > App management > Select App > Clear Storage data or Caches.
realme UI 1.0 & 2.0: Settings > App management > App list > Select App > Clear Storage data or Caches.
realme UI R & Go & T & S Edition: Settings > Apps & notifications > App info > Select App > Clear Storage data or Caches.
Method 2:
Long press the app icon > App info > Clear Storage data or Caches.
Related article:
How to use phone manager to clear storage?