What are they proposing? Is it a sale or rental?
Do they want money to sell the ownership?
Did they contact the owner?
There is virtually no value to resale timeshare ownerships right now almost without exception regardless of location unless it is the top, prime, highest demand time (in which case it MAY be "worth" $5000 or less but even to get that on a great ownership isn't easy). 90%+ of all ownerships have zero resale value despite having a good to great use value for the cost fo annual fees.
So there is NO money to be made for any broker or sales group - if they want to "list" the timeshare or "have a buyer" they are looking for upfront money, no sale will ever occur and the money will be gone as all they promise is, at most, advertising on some obscure website no one ever sees or visits.
If they want to get out of their ownership tell them to give it away for closing costs to someone that sees the use value & is willing to pay the fees. In most cases, especially if they have to ask, that is the only possible value the ownership may have.
DO NOT TRY TO DEAL WITH THIS GROUP is the best advice you & I can offer.