In Resident Evil Requiem, items do not show up on the map until your character gets close to them. The first injector is located in the Blood Lab, but the entrance there is initially locked. To get inside, you will need a Level 1 access pass. You can obtain it by completing the roulette puzzle. 

Steps to obtain the first injector:

  1. Go up to the first floor (upper level) and find the Director’s (Lead Researcher’s) Office.
  2. Make sure to save your progress on the typewriter inside, as a tough enemy encounter awaits you next.
  3. Inspect the body near the office and take the access wristband from it.
  4. Return to the locked Blood Lab doors, open them, and collect the injector together with the blood specimen.

The second injector is waiting for you in the Archive. The same wristband you picked up earlier (near the body) will grant access there as well. Head back to the area you visited at the start and locate the Warden’s Office. There is a staircase next to it. Go up the stairs, enter the office section, and open the door on the right — this is the room where you will find the loot you are looking for. 

The final injector is hidden in the Basement, in the Holding Cells sector. While following the main route, you will notice a cell whose bars are being rammed by a zombie. To get inside, you must first complete the quests involving key items — collecting the three joint plugs and the forklift key in the Processing Room.

You must strictly follow the correct sequence of actions when going for the last injector:

  1. Collect all the required key items.
  2. Under no circumstances insert all 3 joint plugs into the power distributor before picking up the injector.
  3. First enter the newly opened cell and take the loot.
  4. If you decide to activate all the plugs at once, a new story cutscene will trigger and permanently block access to this cell.