Pull requests are welcome! However, it is recommended to open an issue first, especially for feature additions, to allow for prior discussion. Also check the existing pull requests and the roadmap to see if the feature/fix is already planned, in progress, or implemented. If something is planned but not yet in progress, feel free to work on it. Be sure to communicate this (via a draft pull request or some other means) to avoid others duplicating your work.
When developing, work against the develop branch to ensure compatibility with the latest changes. The release branch is specifically for the latest "stable" version; as such, changes are never directly made there.
To run Bubble Wrap locally, you must use a local server. In Visual Studio Code, an easy way to do this is with the Live Preview extension. When Bubble Wrap detects that it's being run on 127.0.0.1:3000 (Live Preview's default port setting) it will activate the testing suite.