Not sure if OP’s one is a hotel or not, but the website did mentioned it’s an app-based key for company, like hotel or maybe business building idk.

https://saltoks.com/

So they probably won’t give you a card anymore, just have to download the app, agree to the permission(hopefully no access needed), and get the key digitally. How safe it is? ¯\_(ツ)_/¯

Edit: the “As a service” thing is probably rental, they provide the equipment and you pay the company monthly.