Using an NFD to sending to non-Algorand chains.

Fetching an NFD via the GET api will return any user-defined addresses for other chains the owner may have set.

They will each be returned as an array of addresses in the top-level property "unverifiedCa" ie:

    "unverifiedCa": {
        "btc": ["xxxxxxxxxxxxxxxx"],
        "eth": ["xxxxxxxxxxxxxxxx"],
    }

All of these values are retrieved from the corresponding userDefined.ca.{token} property. If the full view of the NFD is used, then these properties would be within the properties -> userDefined key. ie:

{
    "appID": 763844423,
    "asaID": 763844429,
    "category": "common",
    "currentAsOfBlock": 21686682,
    "metaTags": [
        "9_letters"
    ],
    "name": "nfdomains.algo",
    "depositAccount": "RSV2YCHXA7MWGFTX3WYI7TVGAS5W5XH5M7ZQVXPPRQ7DNTNW36OW2TRR6I",
    "nfdAccount": "FQDCZYHSK6CHLESEN76AGMSZ4JMT2H5BKWSV6NN2YAKDF22NUAJAOZ4ZIY",
    "owner": "NRLA7VZ2YV6WOS2LBS3UK25DB463XRSNG63BYNQI6CSGGROFWVQ2EKBQSI",
    "properties": {
...
        "userDefined": {
...
            "ca.btc": "xxxxxx"
        }
    },
...
}