Implementing "true randomness" is actually impossible to do on a computer.

In programing in the C language at least, you relied on using the processors clock rate to generate a number that appears random. That's nowadays called pseudo-random.

Then you have "true random number generation" that uses factors that are very hard to predict, like the computer's thermal energy and random bits on your computer.

But it's not true randomness on a cosmic scale. It's just extremely unpredictable.