We have published integration guides for two popular products, Nextcloud and Fortinet

Nextcloud is a suite of client-server software for creating and using file hosting services. Nextcloud is free and open-source, which means that anyone is allowed to install and operate it on their own private server devices. Nextcloud supports passwordless authentication starting from V 19. This guide will show how Token2 FIDO2 keys can be used with Nextcloud Passwordless.
Nextcloud Passwordless with Token2 T2F2 FIDO2 Keys

Fortinet provides various network security solutions such as Next-generation firewalls that provide organizations with application control, intrusion prevention, and advanced visibility across the network. We have published a guide showing how Fortinet appliance administrators can enable two-factor authentication by using standard TOTP hardware tokens or mobile apps.
Hardware tokens for two-factor authentication with FortiGate