Just like most people here said, there is no strategy for playing Plinko as it's a completely random game. I'm not sure about the specific version the OP was playing, but most online casino games have outcomes generated by Random Number Generators (
https://goodluckmate.com/game/guide/rng). These come up with outcomes and no strategy can affect them. Yes, you see Plinko screens, cards on blackjack or the spinning wheel on online roulette. Still, all these are just graphics. The result is generated by a random number generator in the same way for all these online casino games. Of course, live dealer tables are a different story only, but the OP wasn't talking about those.
Many new players don't understand this concept and they have false beliefs that they can somehow impact the outcome or perform better. In reality, casino games are games of luck. You may win 10 times in a row or lose 10 times in a row. You may win a seemingly impossible bet and then lose bets with high likelihoods. There are no rules except the rule that everything is random.
So, my advice is to have a budget (money you're willing to spend and money you can afford to spend) and just play for fun. If you win - awesome! If you lose, you were ready for that to happen and at least you had a great time. Any different attitude can be dangerous.
Whatever you choose - GoodLuckMate!