How do I exchange my grand launch coins?

At top of window is button to exchange them for the box.

Good day Adventurer!

 

You can see a Gift box icon in the right side of your map, click it the go to grand launch fiesta corner, there you can exchange you grand launce coins. 

Says less then 3 hours left for grand launch event and 7th day hasn’t even unlocked for me yet. What happens If events ends I don’t get grand launch chest?