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

Freedom of speech does not apply to:

Fraud

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.

Is visiting holy shrines (dargahs) or graves haraam in Islam?

Perjury

Insurrection

Conspiracy

Main Card Results | UFC 316: Dvalishvili vs O'Malley 2 - UFC.com

False advertising

Insider trading

And much, much more.

How corporate America learnt not to mess with Texas - Financial Times

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.

Child pornography

Trade secrets

150-Million-Year-Old Stegosaurus Skull Rewrites Dinosaur Evolution - SciTechDaily

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.

Revealing classified information

Terroristic threats

Why do companies cull employees during financial downturns without saying so?

HIPAA violations

Threats of violence

No freedom is absolute.

Why do some people enjoy being dominated?

Revenge porn

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.