Fix webvtt format

modules/utils/subtitle_manager.py

@@ -376,7 +376,6 @@ def get_writer(
     output_format: str, output_dir: str
 ) -> Callable[[dict, TextIO, dict], None]:
     output_format = output_format.strip().lower().replace(".", "")
-    output_format = "vtt" if output_format == "webvtt" else output_format
 
     writers = {
         "txt": WriteTXT,
@@ -406,6 +405,7 @@ def generate_file(
     add_timestamp: bool = True, **kwargs
 ) -> Tuple[str, str]:
     output_format = output_format.strip().lower().replace(".", "")
+    output_format = "vtt" if output_format == "webvtt" else output_format
 
     if add_timestamp:
         timestamp = datetime.now().strftime("%m%d%H%M%S")