Delete ONE of these lines, keep only ONE Feather Icons script.

I recommend delete this one:
<script src="https://unpkg.com/feather-icons"></script>

Right before the closing </body> tag, add:
<script>
feather.replace();
</script>
Without calling feather.replace(), Feather icons won't render.

about.html

@@ -15,8 +15,7 @@
     <title>About Us - Amplify</title>
     <script src="https://cdn.tailwindcss.com"></script>
     <script src="https://cdn.jsdelivr.net/npm/feather-icons/dist/feather.min.js"></script>
-    <script src="https://unpkg.com/feather-icons"></script>
-    <script src="https://www.360cities.net/lib/embed.js"></script>
+<script src="https://www.360cities.net/lib/embed.js"></script>
     <script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
     <style>
         @import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Montserrat:wght@400;600;700&display=swap');
@@ -497,5 +496,8 @@ VANTA.GLOBE({
         // Feather icons
         feather.replace();
     </script>
+    <script>
+        feather.replace();
+    </script>
 </body>
 </html>

currency.html

@@ -14,8 +14,7 @@
     <title>Amplify - Currency Exchange</title>
     <script src="https://cdn.tailwindcss.com"></script>
     <script src="https://cdn.jsdelivr.net/npm/feather-icons/dist/feather.min.js"></script>
-    <script src="https://unpkg.com/feather-icons"></script>
-    <script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
     <link rel="stylesheet" href="style.css">
     <style>
         @import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Montserrat:wght@400;600;700&display=swap');
@@ -837,5 +836,8 @@ VANTA.GLOBE({
             setInterval(fetchExchangeRates, 5 * 60 * 1000);
         });
     </script>
+    <script>
+        feather.replace();
+    </script>
 </body>
 </html>

events.html

@@ -15,8 +15,7 @@
     <title>Events Calendar - Amplify</title>
     <script src="https://cdn.tailwindcss.com"></script>
     <script src="https://cdn.jsdelivr.net/npm/feather-icons/dist/feather.min.js"></script>
-    <script src="https://unpkg.com/feather-icons"></script>
-    <script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
     <style>
         @import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Montserrat:wght@400;600;700&display=swap');
         .hero-gradient {
@@ -408,6 +407,9 @@ calendarGrid.appendChild(dayCell);
                 });
             });
         });
-</script>
+    </script>
+    <script>
+        feather.replace();
+    </script>
 </body>
 </html>

help.html

@@ -16,8 +16,7 @@
     <title>Help Center - Amplify</title>
     <script src="https://cdn.tailwindcss.com"></script>
     <script src="https://cdn.jsdelivr.net/npm/feather-icons/dist/feather.min.js"></script>
-    <script src="https://unpkg.com/feather-icons"></script>
-    <script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
     <link rel="stylesheet" href="style.css">
     <style>
         @import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Montserrat:wght@400;600;700&display=swap');

index.html

@@ -16,8 +16,7 @@
     <title>Amplify - Mental Performance for Champions</title>
     <script src="https://cdn.tailwindcss.com"></script>
     <script src="https://cdn.jsdelivr.net/npm/feather-icons/dist/feather.min.js"></script>
-    <script src="https://unpkg.com/feather-icons"></script>
-    <script src="https://www.360cities.net/lib/embed.js"></script>
+<script src="https://www.360cities.net/lib/embed.js"></script>
     <script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
     <style>
         @import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Montserrat:wght@400;600;700&display=swap');
@@ -709,5 +708,8 @@ VANTA.GLOBE({
 // Feather icons
         feather.replace();
     </script>
+    <script>
+        feather.replace();
+    </script>
 </body>
 </html>

pricing.html

@@ -14,7 +14,7 @@
     <title>Amplify - Pricing Plans</title>
     <script src="https://cdn.tailwindcss.com"></script>
     <script src="https://cdn.jsdelivr.net/npm/feather-icons/dist/feather.min.js"></script>
-    <link rel="stylesheet" href="style.css">
+<link rel="stylesheet" href="style.css">
     <style>
         @import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Montserrat:wght@400;600;700&display=swap');
         .hero-gradient {
@@ -349,5 +349,8 @@ const mobileMenuButton = document.getElementById('mobile-menu-button');
             feather.replace();
         });
     </script>
+    <script>
+        feather.replace();
+    </script>
 </body>
 </html>

results.html

@@ -14,8 +14,7 @@
     <title>Amplify - Success Stories</title>
     <script src="https://cdn.tailwindcss.com"></script>
     <script src="https://cdn.jsdelivr.net/npm/feather-icons/dist/feather.min.js"></script>
-    <script src="https://unpkg.com/feather-icons"></script>
-    <script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/vanta@latest/dist/vanta.globe.min.js"></script>
     <link rel="stylesheet" href="style.css">
     <style>
         @import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Montserrat:wght@400;600;700&display=swap');
@@ -457,5 +456,8 @@ VANTA.GLOBE({
             feather.replace();
         });
     </script>
+    <script>
+        feather.replace();
+    </script>
 </body>
 </html>