How to pronounce "firstly:"

Firstly, your articles have been greatly appreciated. I got a lot of calls.

But all of this did not go according to plan, firstly because lightning is super dangerous,

Firstly, sex work is and always has been a survival strategy

Firstly and most crucially, the lab coat wasn't white, it was in fact grey.

So firstly, thinking just about precognition, as it turns out,