For halachic and water safety reasons, it is preferable for an attendant to observe your immersion. An option to minimize contact would be as follows; it would work best if you can discuss it in advance with the attendant.
You can ask the attendant to allow you to enter the mikveh room on your own. Either bring your bag with you and put the towel down on it, or place the towel on a freshly disinfected surface. Call to the attendant when your body is in the water, and ask her to observe the immersion itself from the doorway. She can then leave until you are out of the room.
May we all merit good health and good news!