see systemd.unit(5), systemd.service(5), systemd.socket(5), systemd.device(5), systemd.mount(5), systemd.automount(5), systemd.swap(5), systemd.target(5), systemd.path(5), systemd.timer(5), systemd.slice(5), systemd.scope(5) systemd.link(5), systemd.netdev(5), systemd.network(5) and honorable mentions podman-systemd.unit .container, .volume, .network(…again), .kube, .image, .build and .pod
You create a (self-signed) CA certificate, put its certificate as the client ca in your web server.
Then you can create certificates using this CA that you distribute to your devices, only devices that have a certificate signed by your CA are allowed to connect.