You can download the official trial for free. It’s not time-limited, though a few keys are muted and you have to restart it every 20 minutes.
If you’re looking for a legal, affordable way to use Pianoteq: pianoteq cracked
Pianoteq is developed by a small, dedicated team of mathematicians and acoustic experts. Supporting them ensures they can continue to refine the technology and bring us the most realistic digital pianos on the market. You can download the official trial for free