Ciao, abbiamo una vasca che è un po ‘alta. Conosci una società che apporta modifiche a vasca simile all’immagine allegata? Grazie in anticipo per il tuo aiuto

I’m not sure if normal bathtubs can be modified to do something like this, but of it’s too high maybe get a little plastic two step stool with anti-slip rubber on it?

Well, you have to change the tube entirely. 
Difficult to say how much this will cost because all depends on the tiles and finitions around. 
But you are easily talking about a 5 to 10 k€ of costs here.