You re going to need 3 holes. Let the plumber drill them If you 'slip up',
you 'll risk ruining the whole thing

I have the faucet, and I drilled a 3/4" hole becuase that slightly
exceeded the diameter of the threads on the faucet. But then I
realized that the plumbing part of the faucet has a wider part.
Anyway, it's hard to explain, but the bottom line is that I don't know
what size holes to drill and how to determine it.