Oop 3bet line check

10plo - coinpoker - no min vpip

Was turn bet ok? or we supposed to check/fold turn?
River bet is fine? or bigger? or check is preferred??

Hero (UTG): 100 BB
CO: 111.5 BB (VPIP: 33.33, PFR: 0.00, 3Bet Preflop: 0.00, Hands: 9)
BTN: 95.3 BB (VPIP: 50.00, PFR: 0.00, 3Bet Preflop: 0.00, Hands: 2)
SB: 125 BB (VPIP: 23.75, PFR: 18.75, 3Bet Preflop: 3.33, Hands: 84)
BB: 102.9 BB (VPIP: 27.50, PFR: 7.50, 3Bet Preflop: 0.00, Hands: 40)

5 players post ante of 0.1 BB, SB posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 2 BB) Hero has 7♠ 8♣ A♠ 6♦

Hero raises to 3.5 BB, fold, BTN raises to 12 BB, fold, fold, Hero calls 8.5 BB

Flop: (26 BB, 2 players) T♣ 9♠ K♦
Hero checks, BTN checks

Turn: (26 BB, 2 players) 9♥
Hero bets 13.5 BB, BTN calls 13.5 BB

River: (53 BB, 2 players) 4♣
Hero bets 27.6 BB, BTN calls 27.6 BB