Local AR payment apps generally require a DNI, or via regular banks at the very least, a CDI when opening an account (stand in for a CUIL/T for non-resident foreigners, like an ITIN in the US).
As others have said, there are some other options, but the MEP closed today at $997, which should put the Visa exchange rate at around $925 tomorrow (or Tuesday, not sure if they update on Saturdays) which depending on the fees WU charges you, will be your best bet besides selling dollars on Florida Street considering the crypto exchange rate is ~$954 and WU is $922.10 before fees.
