2. Serve the `build/` folder locally, and access the application via a browser.
For more information on running a local server see [https://developer.mozilla.org/en-US/docs/Learn/Common_questions/set_up_a_local_testing_server](https://developer.mozilla.org/en-US/docs/Learn/Common_questions/set_up_a_local_testing_server). This simple approach has one downside: refreshing the page will give a `404` because of how React handles client-side routing. To fix this issue, consider running `serve -s` courtesy of the [serve](https://github.com/zeit/serve) package.
To run on a testnet, make a copy of `.env.local.example` named `.env.local`, change `REACT_APP_NETWORK_ID` to `"{yourNetworkId}"`, and change `REACT_APP_NETWORK_URL` to e.g. `"https://{yourNetwork}.infura.io/v3/{yourKey}"`.
If deploying with Github Pages, be aware that there's some [tricky client-side routing behavior with `create-react-app`](https://create-react-app.dev/docs/deployment#notes-on-client-side-routing).
**Please open all pull requests against the `beta` branch.** CI checks will run against all PRs. To ensure that your changes will pass, run `yarn check:all` before pushing. If this command fails, you can try to automatically fix problems with `yarn fix:all`, or do it manually.