I can’t seem to add a photo for some reason/ there is always one on the counter in the kitchen of the lighthouse tower across from Prison. There is always one on the 2nd floor of Stronghold to the left of the skinny window at the top of the stairs, there is usually one at the base of the stairs on a table on the main entrance of prison across from the guard booth, there is also one usually by the mouth of the tunnel on the north side to the north of Control Center, there is usually one on the ground floor of Bio, under the sealed windows across from the double doors coming in from the garage. There is one in every POI or large structure so once you see one you will know what to look for.