It depends on a few things.

1. What species is it? I have two indoor trees. One is a dracaena (also known as a dragon) The other is a cedar. The dracaena is a houseplant so I only water it once or so a week. The cedar however, is from outdoors. Its still young though, so I generally do every three days.
2. What pot is it in? A few things to consider are how big is the pot, does it have a drain hole, and how moist is the soil already?
3. How much light? The more light, the more water. The less light, the less water. My dracaena, for example gets light only five hours per week by LED because its winter. So this time of year, I water even scarcer. In the peek times of summer though, I may water it once a day.

I would recommend looking up the correct amount of water for the tree, than substituting for light ans pot size. Hopefully that helps.

Acqua solo quando il terreno superiore è asciutto - due volte a settimana dovrebbe essere sufficiente, ma spruzza leggermente ogni giorno con acqua a temperatura ambiente. Tutto il meglio!