App-Only Install | Developer Documentation

You can configure Embedded Signup so that only business tokens can be used to access assets owned by customers onboarded via the flow. This approach offers enhanced security by reducing risk associated with system tokens, flexibility in simplifying onboarding for other Meta assets, and scalability to support a larger number of onboardings. By using a granular token, you can also reduce the negative impact in case of a compromised token, making it a more secure and efficient way to manage your business customer assets.

Note that App-Only Install can't be used to onboard WhatsApp Business app users.