Signing a transaction is similar to identify Zilliqa:
const boltX = (window as any).boltX;
if (typeof boltX === "undefined") throw new Error("BoltX extension not installed");
const result = await boltX.zilliqa.wallet.connect();
if (result !== boltX.zilliqa.wallet.isConnected)
throw new Error("BoltX could not be connected to.");