Parsing Json in powershell

Question

I have an automation runbook in azure that receives a json string in a variable like so:

["value1","value2"]

The problem is that I can't figure out how to handle this variable and parse it.

$array = "'$jsonInput'"
$Services = $array | ConvertFrom-Json
switch($Services)
{
    value1 { $requested = $true ; break }
    Default { $requested = $false }
}

Using only single quotes does not resolve my input variable. Using "'$jsonInput'" does nothing and the variable $requested returns false. I believe this is because of the use of double quotes in the input variable. What is the correct way to parse this?

If I manually enter this when testing, it works.

$array = '["value1","value2"]'

But then again, not sure how to take this json string without quotes, append the quotes and resolve the variable.