fix of the json upload format

Web/app.py

@@ -11860,7 +11860,12 @@ def batch_upload_page():
     return render_template('upload_batch.html')
 
 
+from flask_wtf.csrf import CSRFProtect
+csrf = CSRFProtect(app)
+
+
 @app.route('/upload_csv_batch', methods=['POST'])
+@csrf.exempt
 def upload_csv_batch():
     """
     Route for batch adding new items to the inventory via CSV.

Web/templates/upload_batch.html

@@ -165,11 +165,25 @@
 
             const formData = new FormData(form);
 
+            const fetchOptions = {
+                method: 'POST',
+                body: formData,
+                credentials: 'include',
+                headers: {
+                    'X-Requested-With': 'XMLHttpRequest'
+                }
+            };
+
+            const csrfToken = document.querySelector('meta[name="csrf-token"]')?.getAttribute('content');
+
+            if (csrfToken) {
+                fetchOptions.headers = {
+                    'X-CSRFToken': csrfToken
+                };
+            }
+
             try {
-                const response = await fetch('/upload_csv_batch', {
-                    method: 'POST',
-                    body: formData
-                });
+                const response = await fetch('/upload_csv_batch', fetchOptions);
 
                 // Antwort einmalig als Text auslesen, um sowohl JSON als auch HTML-Fehler abzufangen
                 const responseText = await response.text();