Asset Type on asset name

Hi,
I’m trying to put the “Asset Type” (BG, CHA…)(sg_asset_type) on the Asset Name of the Maya script, but is not working.

On templates.yaml I set up:
asset_type_name:
type: str
shotgun_entity_type: Asset
shotgun_field_name: sg_asset_type

On Maya template.yaml:
maya_asset_work:
definition: ‘@asset_root/maya/scenes/{sg_asset_type}{Asset}{Step}_{name}_v{version}.{maya_extension}’

But the name added on the script is:
assets_dog01_comp_test_v001.ma

Any clue? Many Thanks!!