Include supported hashes for $argon2() and $pbkdf2(). For $argon2() I assumed was supposed to be the complete hash name.

Code
alias argon2_test {
  var %password = test
  var %salt = kQIfhANrQOtrrBDL
  ; This part is confusing. I assumed it had to be "argon2id".
  var %hash = 2id
  var %derivedKey = $argon2(%password, %salt, %hash, 16, 2, 1, 16)
  echo -ag  %derivedKey
}