Azure Communication Services - Python SDK Call Media not working with CallConnectionClient

it was solved after going through microsoft official docs and i got another error
code snippet:

# Play greeting
                play_source = TextSource(
                    text="Hello, this is your AI assistant. You can start speaking now.",
                    voice_name=VOICE_NAME
                )

                try:
                    call_connection.play_media(
                        play_source=play_source, 
                        play_to=[pstn],
                        operation_context="welcome"
                    )
                    print("Played welcome greeting.")
                except Exception as e:
                    print("Play Greeting Failed: ", repr(e))

        try:
                    call_connection.start_recognizing_media(
                        target_participant=pstn,
                        input_type=RecognizeInputType.SPEECH,
                        interrupt_call_media_operation=True,
                        operation_context="speech-recognition"
                    )
                    print("Started recognition after playCompleted.")
                except Exception as e:
                    print("Recognition start failed after playCompleted.:", repr(e))
            

error:

8565 message: Action failed due to a bad request to Cognitive Services. Please check your input parameters.
i have checked...

• My ACS resource is connected to Speech Resource
• My endpoints for both acs and speech are correct, but i am still getting this error