[caludio]

Why are you all talking about the "reject option", which implicitly considers the opt-in to be the default? The default MUST be the opt-out (for non-essential cookies), hence there is no "reject" because there must be the "accept".

[atleta]

You can be forced to choose, i.e. you can be presented with a popup. And that popup should have both a reject (opt-out) and an accept (opt-in) option. Well, the latter is not needed but otherwise it wouldn't make sense.

Now a lot of sites play tricks to make the reject/out-out a hard deliberately choice. (Which IS a violation of the GDPR, of course.)