Like all the other things you need to do in Vampire the Masquerade Swansong you also need to find the right trophy guide to free the Vessel at Red Salon. To save your time follow this guide and you won’t have any trouble doing that.
Vampire the Masquerade Swansong: The Right Dose Trophy Guide
First go to the bar so you can collect the excess card.
Then turn left an go to the other bar through the tunnel.
Enter the third door in front which is standing staff only sign.
Go as the road is lading you and enter the elevator so you can go down.
Enter the electrical room and open the secret shelves in which are the Trajax MG.
Send both of them through the mini transporter down to office.
Go back and enter the manager office.
Tak te Trajax MG and put it in the other mini transporter so Vessel can get them.
Once she has consumed them both she will feel free to go back.