...

app/src/main/res/drawable/gradient.xml

+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <gradient
+        android:startColor="@color/color_8eb0ff"
+        android:endColor="@color/color_6473f8"
+        android:angle="0"
+        android:centerX="0.5"
+        android:centerY="0.5" />
+    <corners android:radius="50dp" />
+</shape>
\ No newline at end of file

app/src/main/res/layout/dialog_exit.xml

@@ -76,7 +76,6 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/tv_content" />
 
-<!--        android:background="@drawable/gradient"-->
         <androidx.appcompat.widget.AppCompatTextView
             android:id="@+id/tv_sure"
             android:layout_width="0dp"
@@ -84,7 +83,7 @@
             android:layout_marginStart="8dp"
             android:layout_marginTop="32dp"
             android:layout_marginEnd="32dp"
-
+            android:background="@drawable/gradient"
             android:paddingTop="10dp"
             android:paddingBottom="10dp"
             android:text="@string/sure"