Anybody remember the Business Software Alliance[0] from years ago threatening to audit your company for using unlicensed software? I cannot believe any business would be dumb enough to allow them on their premises to even conduct an audit. Anyone with two brain cells would just laugh in their face.
How exactly are you supposed to do that, when your license includes their right to audit your business? If you refuse them they're going to sue you, and they have far more money to spend on lawyers than your business.
You need to have proof that the software is being used. You also have to provide notice and cannot expect to just walk up and demand inspections. Also, this is a private company so they have no authority to do this.
The primary bit of evidence to the BSA was/is from disgruntled employees "ratting" on their employer. Is that sufficient evidence of a crime to justify a warrant for any TLA to do an investigation? If not, that's the only way you're looking at my computers.
Again, laughing in their face would be my response.
[0]https://en.wikipedia.org/wiki/Software_Alliance