Connecting to grpc

sfgrpc.js

const conn = new jsforce.Connection({
  loginUrl: "https://test.salesforce.com",
});
const connectionResult = await conn.login(username, password);
const orgId = connectionResult.organizationId;
const metaCallback = (_params, callback) => {
  const meta = new grpc.Metadata();
  meta.add("accesstoken", conn.accessToken);
  meta.add("instanceurl", conn.instanceUrl);
  meta.add("tenantid", orgId);
  callback(null, meta);
};
const callCreds = grpc.credentials.createFromMetadataGenerator(metaCallback);
const combCreds = grpc.credentials.combineChannelCredentials(
  grpc.credentials.createSsl(root_cert),
  callCreds
);
const client = new sfdcPackage.PubSub(
  "api.pilot.pubsub.salesforce.com:7443",
  combCreds
);