Switches, bulbs, or the wiring behind them
There are three honest ways to make a light smart, and they suit different houses. A smart bulb is the cheapest and needs no electrician, but it is defeated the moment somebody flicks the wall switch off. A smart switch or dimmer module sits behind the existing plate, which keeps the wall working the way everyone expects and makes the whole circuit controllable, including the fixtures you already own.
The third way leaves the fixture alone entirely and makes the circuit smart at the switchboard. Which of the three suits you depends on your wiring, your fittings, and whether there is a neutral at the switch. That is a decision to make after looking at the house, not before.