Ethereum Gas fees when buying with fiat

Apologies if this is a recurring question, but I could not find a clear answer, only talk about transactions in general or smart contracts specifically.

What I would like to know is whether Eth Gas fees apply when buying with fiat? Specifically, I would like buy Eth on Kraken with fiat (i.e. depositing fiat on kraken en then buying Eth with those Euros).

Thank you!