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

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.

And much, much more.

Threats of violence

Are democrats eating crow?

Insurrection

No freedom is absolute.

Perjury

Why Sonics expansion talk could heat up this summer - The Seattle Times

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.

Revealing classified information

Fraud

Your ketchup will see you now: Solid-phase properties reveal when yield stress fluids start to flow - Phys.org

Freedom of speech does not apply to:

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.

Trade secrets

Marc Maron to End His Long-Running WTF Podcast - Pitchfork

Insider trading

HIPAA violations

Child pornography

'City-Killer' Asteroid Even More Likely to Hit The Moon in 2032 - ScienceAlert

Revenge porn

False advertising

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.

More dental problems as you get older? Aging may not be the real reason - San Francisco Chronicle

Conspiracy

Terroristic threats