Continual learning in xgboost

Hi

I am planning on using continual learning in XGboost. In python, it would work as below:

https://xgboost.readthedocs.io/en/latest/python/python_api.html#xgboost.XGBRegressor.fit

Can anyone please point me how to pass the saved model or how to use the xgb_model in Julia implementation please

thanks!