A carburator has several vents, including the float-bowl.

In order for a carburator to work with a turbo, all these vents have to be located inside the pressurized system somehow. Some carburators have been made like this, but good luck...

One other way would be to build an airtight "box" around the entire carb, & use the turbo to pressurize that box. I think there was some Maserati Biturbo that was made like that.