If freedom of speech is absolute, how come it's not applied for private spaces and for the Internet?

You have freedom of speech. If I loan you my computer, I can tell you not to use it for certain things, because it’s mine, you have no right to use it, and if I give you permission to use it I can tell you what you can and can’t do with it.

You have freedom to travel. If I loan you my car, I can tell you not to take it out of town, because it’s mine, you have no right to use it, and if I give you permission to use it I can tell you what you can and can’t do with it.

Perjury

Is parental involvement in their daughters' marriages beneficial? Why or why not?

No freedom is absolute.

Insider trading

Threats of violence

Why Disney’s AI Lawsuit Will Determine Whether Studios Survive - The Hollywood Reporter

Insurrection

Child pornography

If you’re wondering why free speech doesn’t apply to the internet, it’s because you have no right to use other people’s stuff for free.

Fed on Hold Leaves Wall Street Asking What It Will Take to Cut Interest Rates - Bloomberg.com

Terroristic threats

HIPAA violations

Trade secrets

How Elon Musk Is Reinventing Tesla’s Strategy - WSJ

Conspiracy

Fraud

Freedom of speech does not apply to:

32.4 Patch Notes - Blizzard Entertainment

Revenge porn

Revealing classified information

False advertising

The Earth's rotation can be used to generate electricity, as American scientists confirm a two-century-old hypothesis. - Stewartville Star

And much, much more.

That’s what it is. You have no right to use other people’s stuff. If people let you use their stuff, they can tell you how you can use it, and they can tell you to stop using it any time they want.