Create .mp4 stream instead of m3u8

[VirajDeshwal]

Hello, I am trying to create the mp4 format stream for playback. However setting the parameter :
new_asset_settings = mux_python.CreateAssetRequest(playback_policy=[mux_python.PlaybackPolicy.PUBLIC], mp4_support = "standard")

This gives the response :
'new_asset_settings': {'input': None, 'master_access': None, 'mp4_support': 'standard', 'normalize_audio': False, 'passthrough': None, 'per_title_encode': None, 'playback_policy': None, 'test': None},

How can I use .mp4 format with the playback ID to make it work?