Let's Encrypt certificates are so-called Domain Validation certificates. This means that the certificate will only be issued if you can prove that you manage the domain. We demonstrate this by making a file in a protected folder available from your site so that Let's Encrypt can check this. This makes it a requirement that the DNS of a domain refers to us (the site must be live), otherwise the file will not be available on your site.
In practice this works as follows: on every server at Savvii there is a script running every 10 minutes to see if he can reach a set domain (alias) for your site on our server. If so, Let's Encrypt requests a certificate and installs the certificate. After that it takes another 10 minutes before the certificate is activated for your site. So it is not the case that a Let's Encrypt certificate is available immediately after converting the DNS. First our server needs to know that the DNS is finished. This takes as long as the TTL of the DNS-record. If this is set to two hours, it will take a maximum of 2 hours and 20 minutes (and a maximum of 30 minutes less) before the certificate is active on your site. It is not possible for us to circumvent or accelerate this.
If your site doesn't use HTTPS yet, don't switch to HTTPS until the site is live with us.
If you want to put the site live with HTTPS, immediately after converting the DNS, you will have to buy a certificate via billing.savvii.com. We have alternative validation methods for this.