TPGK on flush board but trying to represent a flush (?!)

You could 3bet this hand pre as a bluff.
OTF call is ok.
OTT call is kind of borderline. But maybe that is ok too.
Usually I would not turn my showdown equity into a bluff but villains check makes him look capped indeed. I believe he would bet his flushes here and you can easily rep that.

Preflop is a fold or bluff 3b.
Flop and turn are ok.
OTR just xb and see the showdown. Nothing better is folding here and nothing worse is calling.

I would not try that against an unknown person otr. Otherwise it was ok postflop. Preflop I would have 3bet or folded this hand. This is a very dominated hand against an UTG range

What can Villain make of Hero's play? Villain O/R UTG and Hero calls.
On his CBet Hero calls again with the BU left to act. On the board are a straightdraw and a flushdraw possible. Hero seems savy enough to know that an UTG O/R-hand is one of the better starting hands. In Villain's mind Hero could called preflop with a range which include suited connectors of diamond (straight- and/or flushdraws), a not-premium pair (set).
He might think that Hero floats so he puts in a second CBet but a bit smaller, although the flush has arrived. So has a straight however unlikely. Hero calls again.
Villain doesn't want to inflate the pot, and now Hero bets 72% of the pot this is more than half of Hero's remaining stack. The pot is 99bb and Villain has to to pay 41.5bb to call. This means the pot odds are 2.4 to 1. In this situation he is either way in front or way behind.
On NL2 Villain can't call this bet since most opponents are loose/passive: when they bet they nearly always have the hand they represent. He opts for way behind and folds.
IMO you played this hand fine from the flop onwards.

My opinion:

3bet as a bluff if VI is a good opponent to bluff or fold.
As played, call turn is ok.
OTR: Generally you wanna bluff hands that have no showdown value. But you have showdown value. So why not checking and winning the the same amount?
I just guess a lot of opponents will still call, even if they have AK. And than you bluff out only worse hands but keep in hands that have you beat.

ooh interesting for sure. as far as theory is concerned, if you turn hands as strong as this into bluffs on the river you are betting too much.
as far as practice is concerned, some people tend to check/call a lot of one pair hands like AA and AK and even stronger hands like sets because they really REALLY want to see a showdown but don't wanna bet and get raised, so they check/call and think they are being smart and controlling the pot.

so either way, i don't like the line. you can check behind and win often enough.

Agree with last two posters. The river bluff targets a too slim range of hands. AK and maybe AA. They aren't a dead certain to fold either.