Could do it for free though?
No.
In the United States, a minimum of a commercial pilot certificate is required to fly for compensation or hire. Even if the pilot doesn't get paid, if the jumpers are paying for the flight it's a commercial operation. If the pilot logs the hours, the FAA also considers this compensation every much as if the pilot were getting paid. Pilots have tried to get around the requirement for a commercial in the past by suggesting that they'll just waive the fee...but the FAA has closed that loophole quite some time ago by ruling that the logging of the flight time is compensation. A private pilot may not fly for compensation or hire, or operate a flight which is for compensation or hire.
Working in the United States is another issue.
Finding work in the United States when so many US pilots are out of work is yet another issue. Good luck with that.
Making skydives...always welcome. The world needs more skydivers.