STL to Unity3d conversion

[LORD_BUMBLE]

Trying to import a file into TTS. The website gave it to me in STL format, but TTS does not recognise that file type. I've tried using online file converters, but those files fail to load into the TTS as either asset bundle or model.

Could someone help me translate the file into something I can load into TTS as a model?

[KarvaRausku]

Haven't tried blender have ya? I could take it and put it into obj. file that tts reads.