No-Employer6205's journey

I recently started working with a recruiter for a position that I’m really excited about. However, today I faced a dilemma when she mentioned that if I receive an offer, they would want to contact my current manager for a reference. While I know I'm not a bad employee, I haven’t informed my boss that I’m looking for a new job, and I’m concerned about the implications of this. I wonder if others have been in a similar situation and how they handled it.