To export a model to TFLite, install the required dependencies:

pip install optimum[exporters-tf]
To check out all available arguments, refer to the 🤗 Optimum docs, 
or view help in command line:

optimum-cli export tflite --help
To export a model's checkpoint from the 🤗 Hub, for example, google-bert/bert-base-uncased, run the following command:

optimum-cli export tflite --model google-bert/bert-base-uncased --sequence_length 128 bert_tflite/
You should see the logs indicating progress and showing where the resulting model.tflite is saved, like this:

Validating TFLite model
    -[✓] TFLite model output names match reference model (logits)
    - Validating TFLite Model output "logits":
        -[✓] (1, 128, 30522) matches (1, 128, 30522)
        -[x] values not close enough, max diff: 5.817413330078125e-05 (atol: 1e-05)
The TensorFlow Lite export succeeded with the warning: The maximum absolute difference between the output of the reference model and the TFLite exported model is not within the set tolerance 1e-05:
- logits: max diff = 5.817413330078125e-05.