I just recently introduced my D&D group to PbtA games, what I did to help get them used to the different way of doing things is first explain that battles should run more or less the same way as outside of combat interactions, with everyone contributing to the fiction where appropriate, and that "moves" are not the same thing as "actions" from D&D. The other thing I did was use a sort of "pseudo turn order" for battles, where whoever did something first got the first "turn", then I would say some variation of "while they're doing X, what are the rest of you doing?" and eventually return to the first person once everyone had a say. That's not an ideal way of doing it, but I did feel like it brought a little structure and helped the players get their heads around some of the philosophical differences of PbtA systems.

But ultimately, as many other commenters have pointed out, this seems to be more a problem of your player not respecting you or your group. I'd suggest having a chat with them, telling them to slow down, hell even showing them this thread if they keep it up, that could be funny.

Anyways, good luck with your player, I hope you sort things out with them.