Quick messages are the short messages that you can send to your teammates during your matches quickly. You can change quick messages by following steps :

1. Go to [Inventory] on Lobby page; 

2. Click the "Square" icon on your right side;

3. Click the "Microphone" icon ; then the screen will show you in-game messages in the left part, and the right part are the optional messages;

4.Click the [change] button to edit the quick message