What are the parameters and usage scenarios of the bypass breaker on the Zendure PowerHub 1P?

What are the parameters and usage scenarios of the bypass breaker on the Zendure PowerHub 1P?

Rated at 63A×3. It only closes when the Zendure PowerHub 1P fails and shuts down, switching to bypass power supply to maintain household grid power. Closing it is strictly prohibited in grid-tie mode.