A set of Nextcloud two-factor providers to send authentication codes via Signal, SMS, Telegram, WhatsApp and XMPP.
This app uses external messaging gateway services for sending the code. See the admin documentation on how to configure the specific providers.
All modern applications communicating with Nextcloud now use Login flow so you will be able to log in just like you would on the web, including, but not limited to SMS-based authentication.
Absent support for the Login flow, after enabling Two Factor SMS, your legacy applications will accept device passwords. Read more on managing devices.