The way to stop the windmill in Baldur's Gate 3 is to find the brake switch behind the non-car. After pressing the switch button, the windmill can be stopped. After that, it is relatively easy to complete the corresponding tasks.
Answer: Find the switch directly behind the windmill, select the brake and be careful not to touch or go upstairs.
Then just save, turn on the switch on the left and then load the file.
The first is at the location of the windmill in the northwest of the infected village. The goblins tied the dwarf to the windmill.
Afterwards, approaching them will trigger the plot. Players can choose to defeat the goblins directly or drive them away.
Enter the windmill and directly select the brake button on the left to stop the windmill.