Hi @Ehsan344,
A warm welcome to the Bunnings Workshop community, it is fantastic to have you with us.
Luckily, that is a fairly easy repair. Simply put a generous amount of wood glue, such as this Gorilla Wood Glue, into the split, then clamp it tight with a couple of Craftright Quick Action Clamps.
Wipe off any glue that squeezes out and then allow it to sit for 24 hours before removing the clamps.
Let me know what you think and if you have further questions, please don't hesitate to reach out.
Jacob
