How to use the @decentralized-identity/sidetree.SidetreeBitcoinProcessor function in @decentralized-identity/sidetree

app.use(router.routes())
  .use(router.allowedMethods());

// Handler to return bad request for all unhandled paths.
app.use((ctx, _next) => {
  ctx.response.status = 400;
});

const port = process.env.SIDETREE_BITCOIN_PORT || config.port;

// initialize the blockchain service and kick-off background tasks
let server: any;
let blockchainService: SidetreeBitcoinProcessor;
try {
  blockchainService = new SidetreeBitcoinProcessor(config);

  // SIDETREE_TEST_MODE enables unit testing of this file by bypassing blockchain service initialization.
  if (process.env.SIDETREE_TEST_MODE === 'true') {
    server = app.listen(port);
  } else {
    blockchainService.initialize()
    .then(() => {
      server = app.listen(port, () => {
        console.log(`Sidetree-Bitcoin node running on port: ${port}`);
      });
    })
    .catch((error) => {
      console.error(`Sidetree-Bitcoin node initialization failed with error: ${error}`);
      process.exit(1);
    });
  }