Use Azure Data Factory to iterate over JSON and use values in parameters

Question

I am attempting to automate downloading files from various sections of an FTP Server.

Thinking of having a JSON file that will have the relevant credentials, which would need to be iterated through to obtain the information and pass this as parameters to the FTP connection.

I've tried going through:

1. "Lookup" to the JSON file to obtain the array
2. "Set variable" for the JSON array
3. ForEach - to run through the JSON file

But I can't seem to get this to work.

I've followed the steps in here as a starting point but to no avail.

The main achievement of this exercise is to iterate over the JSON file and pass through the values as parameters in a ForEach Loop.

The JSON file is structured as follows (example):

{
    "FilesToGet": [
        {
            "Description": "<Desc>",
            "Username": "<Username>",
            "Password": "<Password>",
            "Subfolder": "<FTP_Subfolder>",
        },
        {
            "Description": "<Desc>",
            "Username": "<Username>",
            "Password": "<Password>",
            "Subfolder": "<FTP_Subfolder>",
        }
    ]
}

This is the set up I have tried so far.

Another point to note is that I am thinking of storing the JSON file in Azure Key Vault (as it will contain sensitive info) - would iterating over this and passing the info to parameters still be viable?