How can I finetune a model from OpenAI's Whisper ASR on my own training data?

I use OpenAI's [Whisper](https://github.com/openai/whisper) python lib for speech recognition. I have some training data: either text only, or audio + corresponding transcription. How can I finetune a model from OpenAI's Whisper ASR on my own training data?

asr data languagetechnology openai training training data whisper