luci/applications/luci-app-frpc/root/usr/share/rpcd/acl.d/luci-app-frpc.json

{
	"luci-app-frpc": {
		"description": "Grant access to LuCI app frpc",
		"read": {
			"uci": ["frpc"]
		},
		"write": {
			"uci": ["frpc"]
		}
	}
}