Digital ID in Estonia is government-managed and comes for free for everyone with your physical ID. When you get your physical ID you also get the corresponding passwords to use the same ID online with a card reader etc. You can use all online services etc with the above without any extra fees. In addition to that, all telecom companies offer a cheap (usually free if you're on a recurring plan) tie in authentication with your phone where you can use your mobile to authenticate instead of a card reader.