...

app/src/main/java/com/base/pdfviewerscannerwhite/ads/admob/AdmobNativeUtils.kt

@@ -141,4 +141,9 @@ object AdmobNativeUtils {
         }
     }
 
+    fun onDestroy() {
+        nativeAd?.destroy()
+        nativeAd = null
+    }
+
 }
\ No newline at end of file

app/src/main/java/com/base/pdfviewerscannerwhite/ui/document/excel/ExcelActivity.kt

@@ -71,6 +71,7 @@ class ExcelActivity : BaseActivity<ActivityExcelBinding>() {
     override fun onDestroy() {
         super.onDestroy()
         binding.mDocView.onDestroy()
+        AdmobNativeUtils.onDestroy()
     }
 
     @SuppressLint("ClickableViewAccessibility")

app/src/main/java/com/base/pdfviewerscannerwhite/ui/document/pdf/PdfActivity.kt

@@ -85,6 +85,7 @@ class PdfActivity : BaseActivity<ActivityPdfBinding>(), PdfView {
     override fun onDestroy() {
         super.onDestroy()
         muPDFCore?.onDestroy()
+        AdmobNativeUtils.onDestroy()
     }
 
     override fun initView() {

app/src/main/java/com/base/pdfviewerscannerwhite/ui/document/ppt/PptActivity.kt

@@ -87,6 +87,7 @@ class PptActivity : BaseActivity<ActivityPptBinding>() {
     override fun onDestroy() {
         super.onDestroy()
         binding.mDocView.onDestroy()
+        AdmobNativeUtils.onDestroy()
     }
 
     override fun initListener() {

app/src/main/java/com/base/pdfviewerscannerwhite/ui/document/word/WordActivity.kt

@@ -344,6 +344,7 @@ class WordActivity : BaseActivity<ActivityWordBinding>() {
     override fun onDestroy() {
         super.onDestroy()
         binding.mDocView.onDestroy()
+        AdmobNativeUtils.onDestroy()
     }
 
 }
\ No newline at end of file