What are the best ways to confirm that an online poker site is rigged?

Although I have heard of sites being rigged, I can't confirm whether it has ever happened to me.

I was about downloading the WSOP mobile Poker app, but there were many commenters claiming that the game was rigged. After that, I didn't download the app. Maybe they were just poor losers, but there were so many commenters (at least in Spanish) that I took the topic seriously.

My question is: Does anyone know of a reliable method to determine if a game server has been rigged or is it truly random?

*I don't want to get into a philosophical and deep discussion about randomness. I care more about the honesty of the execution than whether it uses a strong or weak random algorithm.

This question is being dupemarked. Despite the example, this question is not connected to any particular server. This is a theoretical question. I am not satisfied with the answer to my question in the dupe-suggested questions.

The greatest risk comes not from non-random hand, but insiders who can see the hands (or at least some of them) in real time while they are being played out. This kind of thing was evident in the Absolute Poker scandal, which occurred 10 years ago. Do current sites do this type of thing? Although it's difficult to prove, there would be no need for random commenters on the iTunes app store to provide evidence.

In the early days of online poker, there was a case with Planet Poker that involved a flawed shuffling algorithm that allowed it to predict the hole cards. Although this was not a problem with random number generation and it wasn’t “rigged,” it shows that software flaws can cause serious problems in games. It's not obvious that anything like this is still happening.

It seems safe to assume that those who post comments about sites being rigged don't have any evidence backing their claims. To prove that, you would need to have a lot of hand histories and/or inside information such as the Absolute Poker case. case. Are Online Poker Sites Fair Or Rigged?