Should have a `model_type` key in its config.json

I have trained a tokenizer from scratch, using:

tokenizer.train(files=[pth], vocab_size=52_000, min_frequency=2, special_tokens=[

I save the tokenizer, I use it to train a BERT model from scratch, and later I want to test this model using:

unmasker = pipeline(‘fill-mask’, model=model, tokenizer=tokenizer)

But it complains that the tokenizer is unrecogized:

“[…] Should have a model_type key in its config.json”

How can I save the tokenizer so that there is a model_type indicated in config.json?