How to deal with slash in OnDownload?

$day = 07/07/2021 - 13/07/2021
{
“Command”: “onDownload”,
“Target”: “A/AAA/weekly/Balabala (${day}).xlsx”,
“Value”: “”,
“Description”: “”
}
And it gave me this:
image

How to deal with it? Thanks.

Slash “/” is not allowed in filenames

You must use a different date format in filename