I need a Cisco CLI/API script to mass update L7 geographical rules to 250+ sites (in same org)

https://developer.cisco.com/meraki/api-v1/#!get-network-appliance-firewall-l-7-firewall-rules

I need a Cisco CLI/API script to mass update L7 geographical rules to 250+ sites (in same org)

Basically the code is done, I just have no idea how to apply it to each router...

{
"rules": [
{
"policy": "allow",
"type": "allowedCountries",
"value": [ "US" <values for some euro countries i dont have off hand> ]
}
]
}