Authelia supports mobile push notifications relying on Duo.
Follow the instructions in the dedicated documentation to know how to set up push notifications in Authelia.
The configuration is as follows:
duo_api: hostname: api-123456789.example.com integration_key: ABCDEF secret_key: 1234567890abcdefghifjkl
The secret key is shown as an example, you also have the option to set it using an environment variable as described here.