Adding one custom word to be recognized

Hello. I'm developing an Android app and I want to add one custom word to the vocabulary list. I'm using light russian model and I do it this way:
`Recognizer recognizer = new Recognizer(model, 16000.f, "[\"глазар\"]");`
Where 'глазар' is the custom word I'd like to add. However, these are the logs:
`W/VoskAPI: KaldiRecognizer():kaldi_recognizer.cc:89) Ignoring word missing in vocabulary: 'глазар'`

I've read manuals on website and checked previous issues, and as I see the only way to solve my problem is to teach the custom model via Kaldi toolkit with prepared 1h voice records for training.

Anyway, I'd like to ask you also, maybe there is a simplier way to do this, without training new model?