Deductible business expense (website fees)

My wife has a SP business (Zumbini and Zumba franchise).  One of the ways she get's clientele is through another franchisee's website.  She receives income only after pre-paying franchise licenses, music codes for franchise IP, transaction/payment fees, rent (pre-pandemic).  Question is this: if she uses another franchisee's website to capture business, and has to pay a peer a fee for using the other person's website, what category is this expense?  It's not technically advertising though the other person's website does cover a wider client base.  Is this a miscellaneous fee?  

 

Just trying be as circumspect as possible with our taxes binning each business expense as the IRS would like them to be.  IRS Pub 535 is woefully lacks the ability to address some the more esoteric deductible business expenses.

 

Please no guesses; only answer if you really know or feel confident about the answer.  Thanks much.