Resolve #3456701 "Passing null to"

src/Form/AdvancedDatalayerDefaultsForm.php

@@ -150,8 +150,8 @@ class AdvancedDatalayerDefaultsForm extends EntityForm {
 
     // Find the current entity type and bundle.
     $datalayer_defaults_id = $datalayer_defaults->id();
-    $type_parts = explode('__', $datalayer_defaults_id);
-    $entity_type = $type_parts[0];
+    $type_parts = $datalayer_defaults_id ? explode('__', $datalayer_defaults_id) : [];
+    $entity_type = $type_parts[0] ?? NULL;
     $entity_bundle = $type_parts[1] ?? NULL;
 
     // Chek if need display only specific tags for this entity type and bundle.