Yes, in select US jurisdictions where BetMGM is legally permitted to operate. New Jersey, Mississippi, and Michigan are the states in question. Withdrawals may be made offline using the Casino Cashier. You may still request a withdrawal online through the Cashier's website.
To get your cash, you must present the system-generated voucher number you were given. You'll also need to provide a government-issued picture ID, such as your driver's license, and be able to verbally supply the last four digits of your Social Security number.