try

templates/index.html

@@ -21,6 +21,7 @@
           <th>Regie</th>
           <th>Medium</th>
           <th>Erscheinungsjahr</th>
+          <th>Aktionen</th>
         </tr>
       </thead>
       <tbody>
@@ -32,6 +33,11 @@
           <td>{{list_all.get("regie")}}</td>
           <td>{{list_all.get("medium")}}</td>
           <td>{{list_all.get("release_year")}}</td>
+          <td>
+            <form action="{{ url_for('delete_movie', movie_id=list_all.get('id')) }}" method="post">
+              <button type="submit" class="btn btn-danger btn-sm">X</button>
+            </form>
+          </td>
         </tr>
       {% endfor %}
       </tbody>