iOS Question i can't clear cache

hello every i have problem in webview with cache i have used all codes and also change webview to WKWebView and use reload function also not work because in my website store when i add new products or remove banner from it the banner have removed from my store but not removed from app also the new products not be shown in my app only shown in my store

in andorid app every thing work fine the problem is in ios app

only work after i reinstall the app can any one help me to fix this problem