Try this:
const processStatusCode = (code) => {
if (code === 401) {
// your logic here
}
};
try {
const result = HTTP.call("POST", 'http://example.com', { data:{"key": "value"}, headers:{'Content-Type' : 'application/json'}});
processStatusCode(result.statusCode);
} catch (error) {
processStatusCode(error.response.statusCode);
}