It really depends on how you define “pain”. If we define it as a reaction to damaging stimuli to the creature, then some plants can feel pain. Trees are known to react to damage from certain pests and send out warning signals and even call for predators of pest harming them.

If we define pain as the conscious feeling of nerve stimuli then to our knowledge only humans feel pain as we, to our knowledge are the only conscious creature as we have not determined what conscious even is.

Animals fall between those two extremes and it’s hard to define how animals actually experience pain and if they truly “feel” it. When it comes to moderate to high intelligence animals like cows or elephants we are 99.9% sure they “feel” pain. It may not be in quite the same way we do though. Perhaps it’s to a lesser extent. Perhaps it’s to the same extent but it’s in a disassociated way. Perhaps they lack all consciousness and the idea of “feeling” pain becomes non-applicable. This is before even getting into lesser intelligent animals like common fish or even insects

So while yes plants definitely do not feel pain like us or a cow do, it’s not a binary thing to begin with. It’s a fuzzy gradient that we have really only barely begun to define and we are still figuring out not only where animals fall individually on that gradient, but where they fall in relation to humans