Unfortunately there is more information needed to answer this question. I would suggest you contact an attorney and set up an appointment to meet and discuss it in detail. The short answer is you don't have to sign the agreement, but that Nevada is an at-will state, so they could fire you for anything, virtually. The details of your situation cannot be solved in a 3 line paragraph. Call Counsel.
The recommendations in this answer are not considered legal advice for the purposes of ethical, legal and practical evaluation, nor does this recommendation create a retention of counsel agreement between us, wherein an attorney-client relationship exists. These recommendations should never be relied upon without first consulting an attorney in your jurisdiction. I am not your attorney, unless we enter into a written agreement fulfilling the terms of that agreement. The comments posted herein are purely for educational purposes and public discourse only.
It is not clear what your question is. Unless altered by limited means, such as a proper express contract providing terms for termination, employment in Nevada is "at will." This means you can be terminated at any time, unless the termination violates public policy. It also means you can quit at any time.
You have not explained how the audit is relevant. Perhaps you can provide more information and clearly state your question so that this community can provide further guidance.
This post is for general informational purposes only. No attempt is made to provide legal advice.