Asking for potty/toilet pre-potty training?

[RockyMountainSky]

Looking for peoples' thoughts on pre-potty training as not quite sure how to manage it.

I have a 20-month-old (two in Feb) and hadn't intended to try and potty train him yet - super young. However, we had a LOT of bathtub poo incidents, so I bought a potty to keep near the tub - have had good success with sticking him on it at the first sign and avoiding a big clean up in the bathtub.

Now he's started asking for the potty himself sometimes - but it seems to be at random and if I try to bring him to it he changes his mind and screams because he wants to keep playing.

I can't tell if I should press on and disrobe him every time he asks and put him on the potty (even if he then starts screaming "no potty"?) or just ignore it until we decide to train him? I don't want bad potty associations but also if he's asking for it maybe he should sit on it every single time?

I suspect this is coming from watching the older kids at nursery potty train but I can't tell if he actually KNOWS he needs it or just thinks it's fun/like a big kid.

Do any more experienced parents have any thoughts about this?