I have heard and seen it in videos is it true?
I am talking about Leafgreen.
Nope. Pressing buttons doesn't increase the chances of catching a Pokemon.
As Mew said, there aren't any ones that are real.
The creators of the game just made that up as a joke.
Everything about that is completely fake.
One I heard about was that you can press A and B while the pokeballs shakes.
Supposibly that would have given a higher catch rate.
But then I looked it up and it was fake also it didnt really work.
So, all in all, it is fake.
Hope I helped!
>Some people claim to have discovered button combinations that increase a Pokémon's catch rate; this is merely idle thought, as there is no method to improve catch rates...
Source: Bulbapedia/ Catch Rate
This is here as a concrete online source.