fix model type

local_perplexity.py

@@ -107,7 +107,7 @@ class Perplexity(evaluate.Metric):
         else:
             device = "cuda" if torch.cuda.is_available() else "cpu"
 
-        model = AutoModel.from_pretrained(model_id, local_files_only=local_file_only)
+        model = AutoModelForSeq2SeqLM.from_pretrained(model_id, local_files_only=local_file_only)
         model = model.to(device)
 
         tokenizer = AutoTokenizer.from_pretrained(model_id, local_files_only=local_file_only)