if Syllabi URL is null .. case handled

app.py

@@ -286,15 +286,18 @@ def favicon():
 @app.route("/extract", methods=["POST"])
 def extract_info():
     data = request.json
-    if not data or "url" not in data:
+    if not data:
         return jsonify({"error": "Please provide a PDF URL in the request body."}), 400
     
-    pdf_url = data["url"]
     try:
-        pdf_text = extract_text_from_pdf(pdf_url)
-        prompt = f"{PROMPT}\n\n{pdf_text}"
-        response = predict_text(prompt)
-        
+        if data["url"] is not None:
+            pdf_url = data["url"]
+            pdf_text = extract_text_from_pdf(pdf_url)
+            prompt = f"{PROMPT}\n\n{pdf_text}"
+            response = predict_text(prompt)
+        else:
+            response = ''
+            
         if data["skills"] == True:
             prompt_skills = f"{PROMPT_SKILLS} using this information only -- {response}"
             response_skills = predict_text(prompt_skills)