Cannot install ghcup on Apple Silicon

Trying to follow the directions for installing ghcup on a new Macbook Air (2020, MacOS 11.1) yields the following error:

20-12-19 9:59 mindbat@mindbat-m1-air ~ % curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh

Welcome to Haskell!

This script will download and install the following binaries:
  * ghcup - The Haskell toolchain installer
            (for managing GHC/cabal versions)
  * ghc   - The Glasgow Haskell Compiler
  * cabal - The Cabal build tool

ghcup installs only into the following directory,
which can be removed anytime:
  /Users/mindbat/.ghcup

Press ENTER to proceed or ctrl-c to abort.
Note that this script can be re-run at any given time.


Unknown architecture: arm64