Good afternoon, would like to connect your site http://keromag.ru/ to https on lezenkript.Odanko, worried that this certificate is given only for 3 months. Tell me please:
Will it need to be renewed every 3 months?
Can I do this automatically?
Will I need to re-register the encryption key every 3 months?
It depends on which client application you use and how you prove your control over the domain name. In many cases, yes.
For example, if you're using nginx on Unix and you originally got your Let's Encrypt certificate by running certbot --nginx, then running certbot renew once or twice per day from a cron job will automatically renew the certificate, without human intervention, when it's 30 days away from expiring.
You don't have to change the encryption key when you renew your certificate, but you do need to prove that you still have control over the domain name or domain names mentioned in the certificate. This can often be done automatically.