How To Report Misuse of Private Messaging

How does one report suspected misuse of the Private Message system? I don't login to Thwack on a daily basis, so the private message I'm reporting was received is a week old. I received a Private Message from Hurtflowers (member since 11/17/2020) telling me I won a Free iPhone 12, but I had to "<click here>" for a chance to win. Other than the Thwack nickname, there was no name, organizatioin, or business provided in the message, which is why I suspect it may not be on the up-and-up.