There are several ways by which you can recharge your Boost Mobile. You can do this by dialling the USSD code, Mobile app or website. Use the USSD code by dialling #111# on your device and following the voice prompt.
Read: how to add data to boost mobile
You can also download the Boost Mobile app from your App Store or Play Store and get everything you need to manage your account including recharges and set up auto-recharge if need be.
