ちなみにproxycheck.ioを使えるようにはPrisMiskey Forkでできるようにしました

if (instance.enableProxyCheckio) {
if (instance.proxyCheckioApiKey == null) throw new FastifyReplyError(400, 'PROXY_CHECKIO_API_KEY_NOT_SET');
const proxyCheck = new ProxyCheck({ api_key: instance.proxyCheckioApiKey });
const result = await proxyCheck.check(request.headers['x-real-ip'] ?? request.ip, {
vpn: 1,
});
if (result[request.headers['x-real-ip'] ?? request.ip].proxy === 'yes') throw new FastifyReplyError(400, 'PROXY_DETECTED');
}