Send broadcast on start is a developer option, which sends an arbitrary broadcast when the cloned app is started. The broadcast is sent as soon as the app’s process is started, before any app activities may (or may not) be shown. This means the broadcast will also get sent when the cloned app starts any background services. The broadcast’s intent is empty and does not have any action nor intent extras set.
You need to specify the the broadcast receiver’s fully qualified component name in the form of <packageName>/<className>. Do not use the abbreviated form of <className>. When declaring the broadcast receiver in the manifest, make sure to mark it exported.
You may also use this option along with the Shared user ID and Process name options to trigger loading an external extension app into the same process as the cloned main app.