How does one get to chat with an opponent or a peer??

Question

chatting

Answer 1

Use the new messenger feraure for the android users and go on the profile whom you want to chat click top right three vertical dots and select message or you can follow whom you want to chat and the message is come on the profile in place of follow and just click that and an default screen will appear where you can message that peer

Answer 2

I realized it's simple click on the users icon once challenge complete. When on user's page click the 3 dots in top right, then message to that person.