5. Repeat

You've resolved the PC's action. The situation is changed, or further revealed, and play snowballs from there.

If the situation is clear and compelling, and one or more PCs are in position to act, then jump straight back to step 3 and ask them, "What do you do?"

If the situation is clear, but things will escalate before the PCs are able to act, then jump back to step 2. Make a soft GM move to show how things are changing. Then ask, "What do you do?"

Likewise, if the situation is clear but kind of static, and the players need a nudge, then jump back to step 2. Make a soft GM move and ask, "What do you do?"

If the situation is unclear, or if it needs recapping or updating, then go back to step 1. Re-establish the situation. Then make a soft GM move and ask, "What do you do?"

If the current scene or situation is over, then wrap things up. Take care of logistics, bookkeeping, and other metagame stuff. Figure out with the players what the next situation or scene should be. If that's not clear, ask questions until it is.

Go back to step 1. Establish the (new) situation, make a soft GM move, and ask, "What do you do?" Resolve their actions. See how the situation changes. Repeat. This is the core loop of the game.