Only You Can Prevent Friendly Casualties Trophy in Call of Duty: Vanguard

Mission 2: Operation Tonga

Near the start of the mission, you will reunite with your teammates in the burning windmill. At the next enemy encounter (the one with a half track) you can find a smoke grenades on a box on the left side of this area. Take them up and keep them with you until later in the mission.

Later on in the mission, you will drive a truck over some mines to explode them and end up inside a ditch, ready to charge a bunker with your allies. Give the order to charge the bunker with  and throw the smoke grenades towards the bunker with .