Introduction to Bash scripting - Flow Control - Loops

I have an issue with that question and I haven’t found any answers valid for it:

Question: Create a “For” loop that encodes the variable “var” 28 times in “base64”. The number of characters in the 28th hash is the value that must be assigned to the “salt” variable.

Answer Code:

#!/usr/bin/env bash

Variables

var=“9M”
salt=“”

for i in {1…28};do
var=$(echo -n “$var” | base64)
done

salt=$(echo “${var}” | wc -c)
echo “the salt is ${salt}”

the characters number is 25224 and still is wrong…
can someone help with that issue?