add element youtube url

backend/app/Element/Element.php

@@ -12,6 +12,7 @@ class Element
         private string $description,
         private string $richText,
         private ?string $pdfPath,
+        private ?string $youtubeUrl,
         private Set $set,
         private ?Element $parentElement,
     ) {
@@ -42,6 +43,11 @@ class Element
         return $this->pdfPath;
     }
 
+    public function getYoutubeUrl(): ?string
+    {
+        return $this->youtubeUrl;
+    }
+
     public function getSet(): Set
     {
         return $this->set;