Thanks!
I had seen that earlier post but it didn't help much for a macOS user. I think there's something a little complex about manually installing .NET 5 to a mac with an ARM processor.
I managed to get it working by downloading the full Visual Studio program for Mac, which included .NET 5. This wasn't an efficient solution, but I'll take it. Downloaded it here: https://visualstudio.microsoft.com/vs/mac/