If you need to create an App via the SDK it can be done like so: 
import { Chains, OpenFormatSDK } from "@openformat/sdk";

const sdk = new OpenFormatSDK({
  network: Chains.arbitrumSepolia,
  signer: process.env.PRIVATE_KEY, // Your wallet's private key
});

// Create App
const app = await sdk.factory.createApp({
  name: "APP_NAME",
});

console.log("APP_ID", app.id);