What does Bonus Buy mean in slots?

In slots, Bonus Buy is a feature that lets the player purchase direct access to the bonus round instead of waiting for it to trigger during regular play.

How does it work?

The player pays a fixed amount, usually many times higher than the base stake, and enters the bonus feature immediately. This may be a round with free spins, multipliers, expanding symbols, or another mechanic that would normally be triggered at random.