Board Game Arena

https://imgur.com/a/r1gw73s

I thought with my 9 character I just draw, I shoud have won. I can't see the button for that. Is it a bug ? Or just me misunderstanding the rules ?

You need a valid yaku to win, and your hand doesn't contain any.

You have called chii which it made your hand is open. And in open hand, riichi can't be called and winning hand don't contain terminal tiles like 1s, 9s or wind, dragon tiles (except some yaku allows to win if you have specifically order of terminal or dragon tiles)