<?php if (!$content->isNew()) { ?>
    <?php if (!isset($node)) { ?>
        <li><a href="<?= $this->url([
            'entity'    => $info->name,
            'action'    => 'edit',
        ], 'core_content', true) . $this->url->query([
            'url' => 'mailto:',
        ], true) ?>" class="btn btn-focus btn-out icon-add">
            New <?= str_replace('URL', 'Email URL', $info->singular) ?>
        </a></li>
    <?php } ?>
<?php } ?>
<?php if (!$content->isNew()) { ?>
    <li><a href="<?= $this->url([
        'entity'    => $info->name,
        'action'    => 'edit',
    ], 'core_content', true) . $this->url->query([
        'url' => 'mailto:',
    ], true) ?>" class="btn btn-focus btn-out icon-add">
        New <?= str_replace('URL', 'Email URL', $info->singular) ?>
    </a></li>
<?php } ?>
--- 
+++ 
@@ -1,10 +1,12 @@
 <?php if (!$content->isNew()) { ?>
-    <li><a href="<?= $this->url([
-        'entity'    => $info->name,
-        'action'    => 'edit',
-    ], 'core_content', true) . $this->url->query([
-        'url' => 'mailto:',
-    ], true) ?>" class="btn btn-focus btn-out icon-add">
-        New <?= str_replace('URL', 'Email URL', $info->singular) ?>
-    </a></li>
+    <?php if (!isset($node)) { ?>
+        <li><a href="<?= $this->url([
+            'entity'    => $info->name,
+            'action'    => 'edit',
+        ], 'core_content', true) . $this->url->query([
+            'url' => 'mailto:',
+        ], true) ?>" class="btn btn-focus btn-out icon-add">
+            New <?= str_replace('URL', 'Email URL', $info->singular) ?>
+        </a></li>
+    <?php } ?>
 <?php } ?>
Fix incorrect add URL button
