PF2e AoO from movement

It seems like there is AoO when you move. It doesn't say anything about needing certain Feats, Abilities or Intellect. Where did you read that Chris?

MOVE ACTIONS THAT TRIGGER REACTIONS
Some reactions and free actions are triggered by a creature using an action with the move trait. The most notable example is Attack of Opportunity. Actions with the move trait can trigger reactions or free actions throughout the course of the distance traveled. Each time you exit a square (or move 5 feet if not using a grid) within a creature’s reach, your movement triggers those reactions and free actions (although no more than once per move action for a given reacting creature). If you use a move action but don’t move out of a square, the trigger instead happens at the end of that action or ability.

Some actions, such as Step, specifically state they don’t trigger reactions or free actions based on movement.

Places like here:

https://www.reddit.com/r/Pathfinder2e/comments/pcgt8t/attacks_of_opportunity/

https://www.reddit.com/r/Pathfinder2e/comments/uypzvz/attacks_of_opportunity_for_everyone/

https://www.enworld.org/threads/less-opportunity-attacks.671840/

Most are just discussions on how Paizo limited the AoO.  The AoO reaction is still there but only for certain classes, feats, and monsters who have that.

Is there anywhere in the book (or the online PF2 Easy Compendium) that specifies only some creatures/classes get AoO when someone moves?
Something that adds to or contradicts what I posted above?

If you look at Ogres in the bestiary the Ogre Boss has the Attack of Opportunity reaction.  All other Ogres do not, even the Ogre Warrior.

Ogre Boss
Ogre Hurler
Ogre Warrior

Others with AoO include the Athach, Skeletal Hellknight, etc.

Then you can look at the Aasimar Redeemer and you can see he has lots of other reactions but no Attack of Opportunity reaction.

Edit:
Wanted to add some NPCs as well.

Abendego Brute has a reaction for movement but it isn't an AoO.
Amihan - Tian-Sing Female Battle dancers do have an AoO and a shield block.
Archery Specialist does not as expected.

But are there written rules about it in the book or the online rules?
Because the rules I posted don't seem to limit who gets AoO's.

The way I read it it does. If you don't have the reaction how would you be able to use it? If I don't have the Shield Block reaction I can't use Shield Block. The text you linked does say that the Attack of Opportunity reaction is triggered by a move action but nowhere does it say that it gives that reaction to everyone/every creature. The most relevant part I see is:

Each time you exit a square (or move 5 feet if not using a grid) within a creature’s reach, your movement triggers those reactions and free actions

but I would put the emphasis on "those reactions".

Without the relavent text giving AoO to everyone and coupled with only certain monsters/NPCs/classes getting the reaction then I would say the intention is that only if you have the reaction can you use the reaction. Otherwise why specifically call out Attack of Opportunity on some monsters? Why make a feat/class feature that does what everyone can already do?

True. You would think they would call that out a little better, especially with this being the remastered version.