Simple MAC List fetch into array into IP Binding

Hey, probably im just too tired to see the issue.Need a poke.

$VarFilename is just the URL

:global strData {[:toarray ([/tool fetch output=user url=“$VarFilename” as-value ]->“data”)]}
:foreach i in=$strData do={
/ip/hotspot/ip-binding :do {add mac-address=“$i” type=bypassed;} on-error={:put “Ouch”}
}

Under the URL I just want to put a simple .txt file that lists the MAC Addresses. Somehow I dont find the correct format to have it converted to an array it seems (it just gets one large string).

I tried some different file formats like

MAC1,MAC2,MAC3

or

MAC1
MAC2
MAC3

or combinations with or without , or " or ; … even escaping the : in the Addresses … to no avail.

use json format inside the file, and appropriate routeros commands for manage json